Objectives: To describe the prevalence of a history of risky sexual behaviours among female prisoners in Concepción-Chile 2016, and to conduct an exploratory analysis of the factors associated with these risky behaviours. Materials and methods: Descriptive crosssectional study with exploratory analysis, conducted in females held prisoners at the "El Manzano" Penitentiary Complex, 18 years of age or older, belonging to the closed jail system, and having already initiated sexual activity. Convenience sampling was used. A background history of risky sexual behaviours, sociodemographic factors, family context and life-style was assessed. Absolute and relative frequencies were calculated for the descriptive analysis, and odds ratios for associated factors. Results: The participants were 73 women in jail. Of them, 60 % initiated their sexual activity before 16 years of age and were teenage mothers. Close to 40% had intercourse under the influence of alcohol or drugs, and close to 20% sexually assaulted at some point in their lives. Approximately 9 % reported not being faithful to their partners or being in a process of situational homosexuality. Prisoners with ≥6 risky sexual behaviours had a higher probability of having suffered family violence (OR = 3.57; 95 % CI 1.05-12.11), abused drugs (OR = 4.83; 95 % CI 1.42-16.40) or alcohol (OR = 3.63; 95 % CI 1.15- 11.42). However, belonging to a Christian religion was associated with a lower probability of risky sexual behaviours (OR = 0.26; 95 % CI 0.07-0.90). Conclusion: The main risky sexual behaviours included sexual activity initiation before 16 years of age, and teenage motherhood. On the other hand, affiliation to a religious ideology was protective from these sexual behaviours.