Gay and bisexual men (GBM) use illicit drugs at higher rates than most other population groups and their use has been associated with sexual risk behavior. The measure of sexual sensation-seeking has been a useful tool for understanding sexual risk behavior in this population, but there is no equivalent measure for sensation-seeking in relation to drug-using behaviors.This paper explores baseline associations with illicit drug use in an online prospective observational study of licit and illicit drug use among GBM. We describe the development of a measure of drug-use sensation-seeking, and its association with illicit drug use.Australian GBM were invited to enroll online through social networking and gay community sites. Between September 2014 and July 2015, a total of 2251 GBM completed the questionnaire and 1900 men provided useable baseline data on items designed to measure drug use sensation-seeking.Mean age was 32.8 years (SD 12.7). Half (50.7%) had used illicit drugs within the previous six months. Among these 963 recent users, 27.3% had used illicit drugs weekly or more often. Responses to items to measure drug use sensation-seeking formed a reliable scale (α=0.944). Within the total sample, any illicit drug use within the previous six months was associated with a higher score on the measure of drug use sensation-seeking (aOR=1.18; 95%CI=1.16-1.20). When we restricted our analyses to men who reported recent illicit drug use, it was also associated with using those drugs at least weekly in the previous six months (aOR=1.09; 95%CI=1.07-1.11).We developed a reliable measure of drug use sensation-seeking for this sample of GBM. Our measure predicted any use of illicit drugs within the total sample, and when restricted to men who reported illicit drug use, it also predicted more frequent use of those drugs.