INTRODUCTION: Cannabis is the most commonly used illicit substance worldwide. Despite this, its impact on sexual health is largely unknown. AIM: The aim of this article is to examine the association between cannabis use and a range of sexual health outcomes. MAIN OUTCOME MEASURES: The main outcome measures include the number of sexual partners in the past year, condom use at most recent vaginal or anal intercourse, diagnosis with a sexually transmissible infection in the previous year, and the occurrence of sexual problems. METHODS: Method used in this article includes a computer-assisted telephone survey of 8,656 Australians aged 16-64 years resident in Australian households with a fixed telephone line. RESULTS: Of the 8,650 who answered the questions about cannabis use, 754 (8.7%) reported cannabis use in the previous year with 126 (1.5%) reporting daily use, 126 reported (1.5%) weekly use, and 502 (5.8%) reported use less often than weekly. After adjusting for demographic factors, daily cannabis use compared with no use was associated with an increased likelihood of reporting two or more sexual partners in the previous year in both men (adjusted odds ratio 2.08, 95% confidence interval 1.11-3.89; P = 0.02) and women (2.58, 1.08-6.18; P = 0.03). Daily cannabis use was associated with reporting a diagnosis of a sexually transmissible infection in women but not men (7.19, 1.28-40.31; P = 0.02 and 1.45, 0.17-12.42; P = 0.74, respectively). Frequency of cannabis use was unrelated to sexual problems in women but daily use vs. no use was associated with increased reporting among men of an inability to reach orgasm (3.94, 1.71-9.07; P < 0.01), reaching orgasm too quickly (2.68, 1.41-5.08; P < 0.01), and too slowly (2.05, 1.02-4.12; P = 0.04). CONCLUSIONS: Frequent cannabis use is associated with higher numbers of sexual partners for both men and women, and difficulties in men's ability to orgasm as desired.