Objective: To examine differences in the frequency of alcohol and drug use by sexual orientation among men and women. Method: The 2011 Gay and Lesbian Press Survey is a cross-sectional, self-administered, voluntary survey available on gay and lesbian websites. Respondents aged 18 or older, residing in France, and who had had sexual intercourse at some point in their lives were included in this analysis. Alcohol use is described by the frequency of consumption in the past twelve months, the number of drinks per day, and the frequency of consuming six or more drinks on a single occasion. Cannabis, ecstasy, or cocaine use is described by the use of these substances one or more times in the past twelve months. The analyses compared, for each gender, sexual orientation as defined by self-identification and the gender of partners. Self-identification as "bisexual" or "gay/lesbian" was available for 2,675 women and 8,725 men; information on the sex of lifetime partners was available for 2,747 women and 9,001 men, and information on the sex of partners in the past 12 months was available for 2,871 women and 8,974 men. Results: While significant sociodemographic and sexual history variations are observed based on self-identification, substance use varies less according to self-identification than according to the gender of partners, for both women and men. Respondents who had partners of both genders reported higher levels of alcohol and drug use. Factors related to lifestyle, psychological distress, or discrimination do not explain these differences in use based on the gender of partners. Conclusion: Understanding the underlying factors driving this use remains a major public health challenge.