BACKGROUND: HIV infection remains a public health challenge. This study assessed sexual practices among casual workers at the Cobblestone construction, Addis Ababa, Ethiopia.
 
 METHODS: This was a quantitative cross-sectional study carried out among the labourers at the Cobblestone construction sites between October – December 2018. Multi-stage sampling was used to estimate the sample size. Demographic and sexual practice information were collected using a structured questionnaire. Bivariate and multivariate analyses were used to determine associations between variables; P < 0.05 was considered statistically significant.
 
 RESULTS: We recruited 627 labourers. Majority (82.2%) were aged between 18 and 38 years; average age at onset of sexual debut was 17.9 ±2.67 and 19.14 ±2.18 years among males and females respectively. Majority (68.5%) were married; exposure to pornography was 40.2% and 32% among male and female respectively. Lifetime multiple sexual practices were prevalent (59.9% and 50.0%) among males and females respectively; extramarital sex was prevalent (66.9%) among males but protected sex was relatively low (46.2%). Being employed significantly associated with likelihood of first exposure to alcohol (P =0.029), level of education, exposure to pornography and knowledge of symptoms of STIs significantly associated with multiple sexual practices.
 
 CONCLUSION: Prevalence of risky sexual practices among the labourers were high which risks them to HIV infections. Innovative approaches to behavioural change are needed to reduce risks of HIV infection.