INTRODUCTION AND AIMS: Use of methamphetamine appears to be greater among gay men than in the general population, yet little data are available on factors associated with use, especially among older men. This study identifies factors associated with reported methamphetamine use among older Australian gay men. DESIGN AND METHODS: Data were collected from an online survey involving 1135 HIV-positive and HIV-negative gay-identified men aged 40 years and older. RESULTS: One in eight men in the sample, or 13%, reported using methamphetamine in the past 12 months. Patterns of reported use were similar across the country, with no significant differences between major states and territories. Reported methamphetamine use was considerably more prevalent among HIV-positive (24%) than HIV-negative men (11%). In a multivariable logistic regression, reported use was significantly greater among men in their 40s compared with those in their 50s and older (P = 0.002), who were single as opposed to being in an ongoing relationship (P = 0.03), who were HIV-positive (P = 0.003), and who reported using other drugs for non-medical purposes in the past 12 months (P < 0.001). Socioeconomic status and psychosocial variables, such as experiences of discrimination and psychological distress, were not significant factors for reported methamphetamine use. DISCUSSION AND CONCLUSIONS: Relatively high rates of reported use of methamphetamine were found across the country in this online sample of older Australian gay men. National approaches to health education strategies may be needed, with a focus on high prevalence populations, such as those infected with HIV.