BackgroundDiscrimination due to sexual orientation (DDSO) has an important association with health outcomes among men who have sex with men (MSM). This study aimed to analyse factors associated with DDSO among MSM in 12 Brazilian cities.MethodsA cross-sectional study with 4,176 MSM participants recruited in 2016 through respondent-driven sampling in 12 Brazilian cities. In this analysis, ordinal logistic regression was used to assess associations with previously identified levels of DDSO, which were based on latent class analysis (LCA) on 13 variables from the discrimination section of the questionnaire. Weighted odds ratios and their respective 95% confidence interval were estimated using Gile estimator. ResultsMost participants were young, single, had a religious affiliation, a post-primary education, were black or mixed race and had a high and average socio-economic status. More than half reported DDSO in the previous 12 months (65%). DDSO was then classified into four latent classes (very high, high, average or low). We observed an independent association among the four latent classes of DDSO and the following variables: age< 25 years old, white skin color, experience of sexual or physical violence, revealing to a father his sexual orientation as MSM, experienced suicidal ideation in the previous two weeks and had taken illicit drugs in the last six months. ConclusionWe observed that sociodemographic characteristics, previous violence experiences, family knowledge about sexual orientation and mental health issues were associated with DDSO. Monitoring DDSO throws into sharp relief our broad social, political, and moral failings. These results should be used for the purposes of surveillance and protection for the human rights.