Objectives Chemsex—using illicit drugs during sex—is prevalent among men who have sex with men (MSM) and associated with sexual and mental health harms. Sexually transmitted disease (STD) clinics are a frequently visited and trusted health care facility for MSM. This study assessed the frequency and extent to which chemsex is addressed by Dutch STD nurses. Methods Of the 24 Dutch public STD clinics, an online questionnaire was distributed in 20 STD clinics (83%) in 2019; the questionnaire was sent to 191 STD nurses, of whom 108 (57%) completed the questionnaire. The main outcome was addressing chemsex during regular MSM consultations, measured on a 5-point Likert scale (never-always). Items measuring knowledge, attitude, self-efficacy, and the social norm were also measured on a 5-point Likert scale (totally disagree–totally agree). Results Of the 108 participating STD nurses, 77 (71%) addressed chemsex regularly or always during MSM consultations. In general, STD nurses indicated to have sufficient knowledge about chemsex (mean [SD], 3.6 [0.5]) and a positive attitude toward addressing chemsex (mean [SD], 4.3 [0.5]). A need for training on chemsex was reported by 82 (76%) STD nurses, especially in signaling problematic chemsex (56/82; 68%). Three STD clinics (15%) had a protocol on addressing chemsex, and 3 STD clinics (15%) had referral pathways to addiction care. Conclusion Sexually transmitted disease nurses from Dutch STD clinics regularly addressed chemsex during MSM consultations. Our results show relevance of educating STD nurses on signaling problematic chemsex and arranging referral pathways to addiction care to optimize chemsex related health care.