Objectives: Engaging in sexual risk behaviour can be a maladaptive strategy for international students to deal with stress. This study examined the role of poor mental health in mediating the relationship between acculturative stress and condom-use intention among international students in Beijing, China. Methods: The study used a cross-sectional design, and the participants were enrolled through convenience sampling. The mediation effects of poor mental health were assessed using structural equation modelling. Setting: Participants included 299 international students (143 men, mean age = 21.87 ± 3.23) who were studying in Beijing, China. Results: Correlation analysis revealed that acculturative stress was negatively associated with condom-use intentions (r = -0.250, p < 0.01) and positively associated with poor mental health (r = 0.458, p < 0.01). Condom-use intentions were negatively related to poor mental health (r = -0.258, p < 0.01). Structural equation model analysis showed that overall poor mental health, as well as anxiety, phobic anxiety and psychoticism, mediated the relationship between acculturative stress and condom-use intentions among men. The same mediation effects for women were not statistically significant. Conclusions: Poor mental health can mediate the relationship between acculturative stress and condom-use intention among male international students in Beijing, China. Findings suggest that programmes and interventions to target acculturative stress and psychological problems may be useful in preventing international students from engaging in sexual risk behaviour.