University students usually consist of young people from culturally and linguistically diverse backgrounds, and a group recognised as being at increased risk of STI. This study found lower levels of STI knowledge and STI testing among international students and to a lesser extent, domestic overseas-born students, compared with domestic Australian-born students. International students exhibited lower risk sexual behaviour but were more likely to have had a HIV test than domestic students. This diversity in sexual health knowledge, sexual health services utilisation and sexual experience indicates the need for a variety of public health approaches to improve sexual health.