Syndemics of poor mental health also drive poorer sexual health outcomes. This study used three scales, the Alcohol Use Disorders Identification Test (AUDIT), the Drug Abuse Screening Test (DAST-10), and the Depression Anxiety Stress Scale (DASS-21) among beneficiaries of sexual health services in Singapore (n =975), respectively. We found that a prevalence of 20.4% and 18.6% of hazardous and moderate-severe alcohol use disorders and substance use risks, respectively. About 13.7%, 18.1% and 10.5% of participants reported severe to extremely severe symptoms of depression, anxiety, and stress, respectively. Further investigation and integrated interventions for mental health in sexual health settings are warranted.