We evaluated the epidemiological differences with respect to demographics, drug use and sexual behaviours associated with lifetime risk of urethritis, genital ulcer disease (GUD) and urethritis and GUD together among 3395 male prisoners in Sindh. Factors associated with urethritis and GUD alone were sex with multiple females, sex with men, and ethnicity. Additional factors associated with urethritis alone were sex with prostitutes, sex with partners having multiple partners and sex with partners believed to be injecting drugs. Behaviours associated with lifetime risk for urethritis and GUD together were sex with multiple females, sex with prostitutes, sex with men, sex with partners believed to be injecting drugs and ethnicity. These relationships were consistently stronger compared to urethritis or GUD alone.