Background: Some specific groups, such as immigrants, are considered at significantly high risk of developing poor sexual health (SH), specifically in relation to sexually transmitted infections (STIs). However, despite the high number of Haitian immigrants living in southern Brazil, a study that assessed the SH of these immigrants has not been conducted yet. Objective: This study aimed to assess the sexual health of Haitian immigrants in southern Brazil. Methods: This was a cross-sectional study conducted in 201 adult Haitian immigrants of both sexes, living in southern Brazil. A self-applied questionnaire containing sociodemographic questions and SH and behaviors was used to collect data. Data were collected on paper or through online form. Findings: Of the 201 immigrants included in the study, the majority were men (58.06%). There was no difference in the mean age (30 years) between both sexes. More than half were married with a partner (a) (53.29%), and 69.89% had an average educational level. Although an association between the reported STIs and the variables considered as risk factors or behaviors for STIs was not reported, women reported a frequency of 33.80% for self-declared active STIs and a frequency of 66.20% for lifelong STIs; these frequencies are highly superior in women compared to men. Additionally, 55.33% of women also reported not using a condom in their last sexual intercourse, and 35.10% reported changing their sexual behaviors after immigrating. Conclusions: The high frequency of STIs reported by Haitian immigrant women indicates the need to implement STI tracking strategies in that population. This study can assist in the development of comprehensive healthcare policies for Haitian immigrants.