Background: The association between sexual dysfunctions and type 1 diabetes mellitus (T1DM) is relatively uncleared. The objective of this study is to evaluate the prevalence of sexual dysfunction in a group of women and men with T1DM and to compare the prevalence in subjects treated with different types of insulin therapy. Methods: The population includes 77 women and 68 men with diagnosis of T1DM of which 33 on Multiple Daily Injections and 112 on Continuous Subcutaneous Insulin Infusion (86 on Advanced Hybrid Closed Loop System with catheter and 26 on patch pump). All participants completed a questionnaire that evaluates several domains of sexual function: the women group filled out the Female Sexual Function Index (FSFI) and the men group filled out the International Index of Erectile Function (IIEF-15). Results: The overall prevalence of female sexual dysfunction (FSD) is 49.3% and the overall prevalence of erectile dysfunction (ED) is 48.5%. Sexual dysfunction appears related to age and dyadic status: in women group, FSD prevalence is statistically significant higher in older groups (p=0.01) and in groups not in a relationship (p<0.01); in men group ED diagnosis was statistically significant more frequent in older subjects (p=0.05) and in subjects not in a relationship (p<0.01). Age and dyadic status is also associated with lower scores in several domains of FSFI and IIEF-15 questionnaires. Conclusion: Subjects with T1DM present a high prevalence of sexual dysfunction. This occurrence is strictly related to age and dyadic status but seems independent of glycometabolic control of the disease and different insulin regimens.