Patients who are critically ill get often admitted to intensive care units (ICUs). The majority of these patients require support with their breathing and are thus connected to a mechanical ventilator. One aspect to consider in the mechanically ventilated patient is endotracheal tube cuff pressure (ETT) management. The management of ETT cuff pressure entails that nurses working in ICUs have the responsibility of ensuring that ETT cuff pressure is kept within normal range of 20-30 cmH20 for the safety of the patients in order to avoid complication of over and under inflation. Poor management of ETT cuff pressure places the mechanically ventilated patients under risk of tracheal injury. Tracheal injury may also be caused by over or under inflation of the ETT cuff. Over inflation of the ETT cuff can lead to the occlusion of capillaries lining the trachea at the cuff site, tracheal stenosis, and can also lead to the death of mucus membranes around the area, just to mention a few. On the other hand, under inflation of the ETT cuff, can lead to air leaks as well as aspiration of gastric contents into the tracheal tree. Therefore, in order to maintain ETT cuff pressure within normal ranges, evidence-based guidelines related to the management of ETT cuff pressure should be used. However, in Malawi the management of endotracheal tube cuff pressure in mechanically ventilated adult patients by nurses in ICUs is not well explored and it is not clear whether this practice is based on evidence-based guidelines. Furthermore, strategies on how to implement evidence-based guidelines in the ICU might not be known and poorly defined because of the complexity of the context. The study is therefore aimed at implementing and evaluating the effect of an evidence-based guideline on the management of ETT cuff pressure in mechanically ventilated adult patients by nurses in ICUs in Malawi using active (printed educational materials and monitoring visits) and passive (printed educational materials only) implementation strategies. The research study used a quantitative approach with multi-designs. Four phases were used in order to achieve the four objectives that were set. Phase one was the pre-test and used a survey design, two was the expert panel review of the evidence-based guideline, three was the implementation of the reviewed evidence-based guideline using a randomised controlled trial design and phase four was the post-test which used a survey design. The RCT included 25 participants from the control and 27 from the intervention group. Each group had three ICUs of which one in each group was from a private hospital and the other were government. Data collection in phases one and four was by a hand delivered pre-and post-questionnaire. In phase two the expert panel members with experience in critical care used the AGREE II Instrument to review the evidence-based guideline that was implemented. In order to gather data during the monitoring visits, the researcher recorded field notes. The applications that were developed by the University statistician consultant using visual basic applications in excel were used to analyse data. Two different implementation strategies were used to implement the evidence-based guideline. The control group used passive implementation strategy which was printed educational materials thus the evidence-based guideline and algorithm. The intervention group used both active and passive implementation strategies which was the printed educational materials thus the evidence-based guideline and algorithm plus monitoring visits by the researcher. In order to establish the effect of the implemented evidence-based guideline on the nursing care practice for the management of endotracheal tube cuff pressure an evaluative posttest survey was conducted in phase four of the research study. The results revealed that the majority of participants had gaps in both groups regarding nursing care practice for the management of endotracheal tube cuff pressure for the mechanically ventilated adult patients in the pretest but improved in the posttest. In the control group 52% had very low knowledge score, 16% had low score, 28% average, and 4% high score while in the category of very high score there was nobody. However, in the posttest those in the very low score were only 44% while the percentage in the low score remained 16%. There was an improvement in the average scores in the posttest such that only 44% were in this category. There was no one in the high and very high score in the pretest. On the other hand, in the intervention group, 78% had a very low score, 9% low score, and 13% were in the category of average score, while in the high and very high score category there was zero percent in the pretest. However, there was also an improvement in the posttest such that only 44% a very low knowledge score. But 19% had a low score, there were 37% in the average category and no one was in the high and very high score. Statistical analysis revealed that the results were not significantly different between and within groups. Improvements were observed in the two groups regarding the scientific knowledge scores for the nursing care practices in the posttest. Upon qualitative analysis of the data from the open-ended question, two main themes emerged thus the need for documentation of endotracheal tube cuff and the process of implementation the evidence-based guidelines. Sub themes such as lack of documentation; no part of routine care and monitoring not done at all were identified under the main theme of the need for documentation of ETT cuff pressure. The Guideline itself need to be clear; implementation strategies; follow up; incentives; supervision; incentives; time factor; resources or equipment required for successful implementation; nurses buy-in critical for the implementation; training detrimental to EBP implementation; nurses attitude crucial to implementation of EBGs and knowledge of nurses for guideline essential for the implementation were the sub themes identified under the main theme of the process of implementing the evidence-based guideline. All appropriate ethical considerations such as principles of autonomy and self-determination, confidentiality and anonymity, voluntary participation, right to receive treatment, informed consent, were adhered to throughout the research study. The research study was unique in nature because it was the first of its kind in Malawi and it contributed to the awareness of the recommended practice for management of endotracheal tube cuff pressure in the ICUs in the country by implementing an evidence-based guideline. The unique contribution of the study is that it is a challenge to implement evidence-based guideline in poor and resource constraint countries like Malawi.