To reduce the HIV-related transmission behaviours of persons living with HIV (PLH), a few efficacious interventions have been designed and evaluated. However, these interventions were delivered at relatively high cost, both in terms of time and resources. Given the challenges for health providers and community agencies in delivering these interventions, alternatives are needed. One possible intervention is allowing PLH to self-monitor their HIV transmission risk behaviour. Previous research suggests that self-monitoring of HIV-risk related behaviours may be a useful risk reduction strategy. This paper examines the impact of repeated risk assessments for behavioural self-monitoring as an intervention strategy for reducing sexual and substance use risk behaviours. A total of 365 PLH, recruited from community clinics, health management organizations, and health departments, completed self-assessments over time. Increased self-monitoring resulted in increases in protected sex with sexual partners of HIV-negative or unknown serostatus, and changes in attitudes conducive to reducing risk. Self-monitoring is a relatively low cost and easily implementable strategy for reducing the HIV-related transmission risk of PLH.