Patterns of club drug use among gay and bisexual men demonstrate that poly-club-drug use is common, and that patterns of use can be differentiated along the lines of age, race/ethnicity, and sexual orientation, with those who are older, Black, and bisexual, reporting less club drug use. The majority of the men initiated use of the five club drugs as follows: cocaine, ecstasy, ketamine, methamphetamine, and GHB. Variations in patterns were related to both age and level of poly-club-drug use. The sequencing and/or patterns of club drug use may be better explained by socialization processes in the gay community than by the Gateway Theory, which has been traditionally used to explain patterns of drug use in the population. Future research is recommended, with an eye toward more closely examining the synergy of drug use combinations with an emphasis on measuring the extent to which the drugs are taken in synchronicity. To document patterns and sequence of initiation of club drug use in a sample of 450 gay and bisexual men in New York City, this paper used quantitative and qualitative baseline data from a yearlong longitudinal investigation conducted between 2001 and 2005. The study focused on the use of five club drugs--cocaine, GHB, ketamine, ecstasy, and methamphetamine--using self-reported indications of use for a period of 4 months prior to assessment. Tables, references