The objective of this study was to analyze the relation between sexual assertiveness and consistency in condom use in a sample of men who have sex with men (MSM) in the Los Altos region of the state of Jalisco, Mexico; 84 MSM voluntarily completed a questionnaire of sociodemographic characteristics, the sexual assertiveness scale, and two questions that evaluated the index of consistency in condom use. The design was quantitative, cross-sectional, descriptive-correlational in scope. The results showed low to moderate levels of sexual assertiveness and a condom use consistency index of 39.3%; there was a positive correlation between sexual assertiveness and consistent condom use (p=0.001). It is concluded that sexual assertiveness is a possible protective factor in the use of condoms at the time of sexual intercourse in MSM, so it is recommended to promote communication and negotiation of condom use during sexual intercourse.