Gay and bisexual men typically report high rates of illicit drug use, including methamphetamine use. This paper aimed to analyse trends in crystal methamphetamine ('crystal') and powder methamphetamine ('speed') use among gay and bisexual men in Australia, and characterise the sociodemographic, drug use, and sexual risk practices of men who reported crystal use.The Gay Community Periodic Surveys, routinely conducted behavioural surveillance surveys of gay men in Australia, were analysed to examine trends in recent crystal and speed use during 2005-14 (any use in the previous 6 months), and trends in regular crystal and speed use during 2007-14 (at least monthly use in the previous 6 months). Covariates of recent and regular crystal use were analysed using 2014 data.Speed use declined from 25.0% to 10.2% during 2005-14 (p-trend <.001), while regular speed use declined from 7.0% to 2.3% during 2007-14 (p-trend <.001). Any crystal use declined from 15.6% to 11.4% during 2005-14 (p-trend <.001) and increased during 2010-14 (from 9.6% in 2010; p-trend <.001). Regular crystal use declined from 6.1% to 4.0% during 2007-14 (p-trend <.001) and remained stable during 2010-14 (3.9% in 2010; p-trend=.64). Participants who reported regular crystal use were more likely than men who used crystal less frequently to have used gamma-hydroxybutyrate, used party drugs for sex, and to have injected drugs in the previous 6 months. High rates of crystal use and injecting were reported among HIV-positive participants.Rates of both crystal and speed use, despite fluctuations, were consistently high throughout the study period. The high rates of crystal use and associations with potentially risky sexual practices indicate that gay and bisexual men should be a particular focus for targeted harm reduction and combined harm reduction and sexual health services.