The purpose of this master‘s thesis was to identify key success factors of IT consulting services, evaluating differences of the perceivable value from the received services between the largest Lithuanian organizations in public and private sectors. The main goals of this paper were to identify the key success factors of IT consulting services through extensive academic literature review; to compare singularity of public and private sectors in IT consulting services context; to conduct an empirical research identifying key success factors; to generalize the key success factors in Lithuanian environment, evaluating the differences and similarities of public and private sector organizations, proposing the ways of increasing the potential value of IT consulting services in Lithuanian market. Key success factors were analysed by reviewing academic literature and conducting qualitative and quantitative research. Seeking to secure the validity of research indicators within Lithuanian cultural conditions, the structured interview with market experts were carried out. The insights and recommendations of the experts were used in the questionnaire of the quantitative research where employees, mainly the chiefs of IT departments from the largest private and public Lithuanian organizations took part. The results of the empirical study indicated the differences of the key success factors between the public and private sectors. The determined key success factors and proposed... [to full text]