Background Recently, swingers are classified as an emerging high-risk group for STI. A well excepted explanation is that swingers have multiple sex partners, concurrent partnerships and engage in high risk behaviour enabling rapid spread of STI. The present study assessed the prevalence of drug use while swinging and the contribution of drug use to STI risk.

Methods In our cohort study we included couples who self identified as swingers and visited the STI clinic in Limburg (2009–2012). Swingers (median age 45 years) filled in a self administered questionnaire to assess their sexual and drug use behaviour in the past 6 months. Using chi-square test associations with drug use were assessed.

Results Of 294 swingers, 49% were female, 48%(n = 140) (49% in men; 46% in women) reported drug use (other than alcohol or erectile dysfunction drugs) while swinging.

Top 5 drugs used were laughing gas (87%), XTC (86%), GHB (79%), cannabis (60%) and poppers (33%). Overall, alcohol was used by 46%. Of men 63% and of women 6% used erectile dysfunction drugs of which Camagra was most reported. Multiple drug use was reported by 90% of the users. Most common combinations include GHB and XTC (67%), XTC and erectile dysfunction drugs (38%), and alcohol and erectile dysfunction drugs (29%). Multiple drug use was associated with low education, swinging at home party’s, swinging more than 2 years, swinging more than 4 times in the last 6 months, more than 5 partners and group sex. Assessment of association with STI is ongoing.

Conclusion Prevalence of drug use in swingers is high. It has been shown that drug use is associated with increased high risk sexual behaviour in different groups and we show this is also the case in swingers who use multiple drugs. Whether drug use is associated with STI will be determined.