The objective of this study was to investigate factors correlated with late treatment initiation in a cohort of patients starting treatment in Mali, West Africa, while focusing on the role of sex/gender. This study consisted of a cross-sectional analysis of baseline data from a prospective, observational cohort of patients initiating antiretroviral treatment in Mali. Patient data were analyzed with a gender perspective to examine factors correlated with late treatment initiation, defined as having a CD4 count below 100 cells/ml. Aday and Andersen’s conceptual framework of access to medical care was used to classify baseline participant characteristics associated with late treatment initiation. Logistic regression was used to evaluate the modifying effect of sex/gender. Results show that 39% of patients initiated treatment late; significantly more of these were men than women. Sex/gender, marital status, and education were associated with late treatment initiation. Unmarried men and uneducated women were significantly more likely to initiate treatment late. Programs need to target unmarried men while being cognizant that uneducated women are arriving late as well.