Résumé : Objectives: The aim of the ISY study was to investigate the prevalence of menstrual-related symptoms prior to and/or during menstrual or withdrawal bleeding among women from 12 European countries. Methods: A 15-min quantitative online survey was conducted in two waves from February to September 2015 among 5728 women aged between 18 and 45 years, with an equal distribution of women using a combined hormonal contraceptive, including regular combined oral contraceptives (COCs) (CHC group, n = 2739) and women using a non-hormonal contraceptive or no contraceptive (non-HC group, n = 2989). Results: The prevalence of at least one menstrual-related symptom was high in CHC users (93%) and in non-HC users (95%) (p <.0001) and the average number of symptoms reported was 5.3 vs. 5.9, respectively, (p <.0001). Pelvic pain, bloating/swelling, irritability and mood swing were reported in more than half of the women in both groups. Although generally modest, symptom severity was higher in non-HC users, except for headache. Overall, during the last four cycles, 60–75% of women did not require a treatment for most symptoms but headaches and pelvic pain. Mood swings/irritability, water retention/weight gain, lack of energy/mood swings and lack of energy/irritability were common symptoms that frequently co-occurred. No associations were reported between symptoms and age, educational qualifications or women’s desire to reduce the frequency of menstruation. Conclusions: Premenstrual and menstrual symptomatology was less frequent, less numerous and less severe (except for headache) in women using CHCs; however, it remains a common concern. Reducing the frequency of menstrual periods could reduce withdrawal-related symptoms.