Equatorial Guinea has one of the highest burden of tuberculosis (TB) in Africa. Incomplete adherence to TB treatment has been identified as one of the most serious remaining problem in tuberculosis control. The following study is aimed at determining the adherence to anti-tuberculosis treatment in Equatorial Guinea and its determinants, as well as at assessing the knowledge of the people about the disease. In this cross-sectional study, participants were recruited by non-probabilistic consecutive sampling amongst patients who attended the reference units for TB in Bata and Malabo between March and July 2015. Socio-demographic and clinical data were collected. Adherence to treatment and knowledge about TB were assessed by Morisky-Green-Levine and Batalla tests and a questionnaire on adherence related factors specifically prepared for this research. Descriptive statistics were computed to summarize the data and bivariate analyses by adherence profile were performed with χ2 test for categorical data. A total of 98 patients with TB were interviewed. 63.27% of interviewees had good knowledge about TB (Batalla test) while 78.57% of respondents were adherent according to the Morisky-Green-Levine test. A low educational level, lack of family support and lack of medical advice about the disease were significantly associated to lower adherence level. Patients with re-infection (due to relapse or treatment failure) and those who have suffered from drug shortages were also less adherents. The National Programme for TB Control should consider improving the early diagnosis and follow-up of TB cases, as well as the implementation of all components of DOTS (Directly observed Treatment, short-course) strategy all over the country.