Objectives To examine the prevalence of unsafe sexual behaviour, sexually transmitted infection (STI)-related knowledge, health and work-related conditions, and correlates of practising unsafe sex among domestic and foreign male workers in multinational workplaces in Jordan.

Design Cross-sectional behavioural assessment survey.

Setting Multinational workplaces in Jordan.

Participants 230 Jordanian and 480 foreign male workers aged ≥18 years who had worked in a Qualified Industrial Zone (QIZ) for 12 months or more.

Outcomes The primary outcome was the prevalence of practising unsafe sex. ‘Unsafe sex’ was defined as sex with a non-regular sexual partner with inconsistent condom usage.

Results Overall, 74.3% of workers reported lifetime sexual experience. The proportion of lifetime unsafe sex was similar among domestic (31.8%) and foreign (35.6%) workers. Of those, 59.2% of domestic and 68.1% of foreign workers started practising unsafe sex after joining the QIZ. Rates of lifetime unsafe sex were significantly higher among those who had their sexual debut after joining the QIZ in domestic (aOR, 2.2, 95% CI 1.1 to 4.4) and foreign workers (aOR, 2.4, 95% CI 1.4 to 4.1). Among the domestic workers, being 18–24 years old (aOR, 4.9), unmarried (aOR, 4.8), working in the QIZ for 5–8 years (aOR, 5.0), sometimes/frequently shopped with foreign workers (aOR, 2.1) or were current/ex-alcohol drinkers (aORs, 3.4) were independently significantly associated with higher odds of practising unsafe sex.

Conclusions A significant proportion of domestic and foreign male workers had been practising unsafe sex. The findings indicated that not only foreigners but also domestic male workers associating with foreign workers are at high risk of unsafe sex. Tailored interventions to promote safer sex in multinational workplaces in Jordan are needed.