This study aimed to investigate the prevalence and correlates of sleep problems in a large prison in China. A total of 1491 incarcerated male adults (35.44 ± 9.67years, range 18-69) were assessed by a self-administered structured questionnaire. Sleep duration, insomnia, sleep quality, substance abuse history, gambling history, traumatic life events, posttraumatic stress disorder (PTSD) and depressive symptoms were measured. Type of offense, history of incarceration, sentence length, and duration in prison were recorded. Multivariate logistic regression was used to examine correlated factors of sleep problems. Overall, 17.4% (95% CI 15.6-19.5%) slept less than 6h at night, 35.6% (95% CI 33.2-38.0%) slept 6-7h, and 47.0% (95% CI 44.5-49.6%) slept 7h or more. The prevalence rates were 26.2% (95% CI 24.0-28.5%) for insomnia and 45.9% (95% CI 43.4-48.4%) for poor sleep quality. Multiple models showed that older age, being divorced/widowed, poor physical health, long duration in prison, drug use before incarceration, PTSD and depression were associated with short sleep duration; while older age, poor physical health, PTSD, depression, and gambling before incarceration were associated with increased incidence of insomnia, and that being divorced/widowed, poor physical health, PTSD, depression, smoking before incarceration were related to poor sleep quality. These findings indicate that sleep loss, insomnia, and poor sleep quality are common in prisoners, and that sleep problems are associated with multiple psychosocial factors.