Introduction and Aims. Mephedrone (4-methylmethcathinone) is a synthetic stimulant that has recently emerged as a recreational drug. There is currently no Australian data on prevalence and patterns of mephedrone use. This paper aims to explore patterns of mephedrone use among a large sample of same-sex attracted young people in Sydney, Australia. Design and Methods. An online survey was conducted with 572 same-sex attracted men (n=318) and women (n=254) aged 18 to 25years, who lived or regularly spent time in Sydney. Data on mephedrone were collected as part of a larger study exploring sexuality and nightlife. Results. Mephedrone had been used by 4.0% (n=23) of respondents, 2.1% (n=12) in the preceding 6months, 1.4% (n=8) in the preceding month. Typical routes of use were intranasal (n=8) and ingestion (n=6). No respondent reported ever injecting mephedrone. Three respondents reported polydrug use with mephedrone. The most common contexts of use were respondents' homes or friends' homes (n=8) and gay bars and clubs (n=7). Discussion and Conclusions. This paper reports low levels of mephedrone use among a large sample of same-sex attracted young people. The proportion of respondents who had used mephedrone was much lower than reported in recent UK research. This may suggest that mephedrone has not infiltrated the Australian market to the same extent as in Europe. However, data from annual surveillance of drug users are required to better determine this.