Despite a rise in breast cancer incidence, mortality rates have fallen. This improvement in mortality is due to the success of anti-cancer treatments such as chemotherapy and radiotherapy. Such treatments, however, are known to be associated with a range of symptoms. A number of studies exploring patients’ chemotherapy-related symptom experiences have shown that patients consistently rate nausea and fatigue highly, not only in relation to severity, but also in relation to the associated distress they experience. The subjective and non-observable nature of both nausea and fatigue complicates their assessment. While a range of assessment tools exists to evaluate patients’ experiences of these two symptoms, there is currently no gold standard assessment tool for assessing either symptom. Moreover, while a range of pharmacological and non-pharmacological interventions have been developed for both symptoms, further evaluation is often needed to provide the level of evidence required to recommend their implementation in real life clinical environments. The SNA↔P (structured nursing assessment into practice) study arose in response to this clinical situation. The SNA↔P study was a longitudinal study that evaluated the impact of a complex evidence-based intervention, incorporating structured multidimensional symptom assessment and multiple symptom management techniques, on patients’ experiences of nausea and fatigue during a course of chemotherapy for breast cancer. Using complementary quantitative and qualitative research methods not only allowed in-depth understanding of patients’ experiences and patterns of nausea and fatigue during a course of chemotherapy, but also facilitated a rounded evaluation of the intervention, incorporating both statistical elements and those of personal significance. The use of these methods showed that the implementation of the SNA↔P intervention in routine clinical practice has significant potential for improving patients’ symptom experiences during a course of chemotherapy. In so doing, it also highlighted a number of areas in which clinical practice can be influenced, and research conducted, to further improve patients’ symptom experiences.