Given the lack of effective vaccine or medicine, changing an individual's risk behaviours has been crucial in preventing the spread of HIV. Consistent and correct condom use has been considered as the most effective form of HIV prevention among female sex workers. Despite coordinated national level interventions over the last decade, a consistent decline in condom use among female sex workers has been evidenced in the Ethiopian context, particularly with non-paying partners. Thus far, no study has been produced that has illustrated major determinants of consistent condom use among female sex workers which would help in developing effective intervention strategies for the prevention of HIV spread in the country. In other countries, the Information, Motivation and Behaviour (IMB) model has been used to identify individual level determents of condom use. However, the researcher postulated that behaviour emanating from the personality structure of individuals could be the fundamental individual level determents of adherence to condom use and chose to investigate this using the Enneagram theory of personality, which was acknowledged for its heuristic value in explaining and enhancing self-development of at-risk individuals. This cross-sectional study was conducted in Addis Ababa. With the Without Finite Population Correction of the Sample Size Estimation Formula, the sample size of 350 was set and participants were recruited using Respondent-Driven Sampling (RDS). Using trained female sex workers, the Essential Enneagram Test (EET) and an Information-Motivation-Behaviour (IMB) questionnaire were administered to collect data. General Linear Modeling (GLM) Multivariate analysis was carried out to assess the correlation between personality style and consistent condom use among participants in the last seven days before the interview. The finding of this study revealed that personality type, measured by the Essential Enneagram Test (EET), is able to predict adherence to condom use among female sex workers and provided a new dimension for policy makers and practitioners in behavioural intervention programmes, such as Information-Education-Communication, peer-to-peer approaches, as well as health and rehabilitation services by using the Enneagram principles and universal growth process. / Psychology / D. Litt. et Phil. (Psychology)