AIM To identify reproductive disturbances among adolescent girls and young women with type 1 diabetes mellitus(T1 DM) in Saudi Arabia.METHODS This cross sectional study was conducted among 102 female with T1 DM,(aged 13-29 years) who attended the Diabetes Clinic at Diabetes Treatment Center, Prince Sultan Military Medical City, Saudi Arabia between April 2015 to March 2016. Clinical history, anthropometric characteristics and reproductive disturbance were collected through a questionnaire.RESULTS Of 102 patients included in this analysis, 26.5%(27/102) were reported that they experienced an irregular menses. Of these patients, when compared to whose diabetes was diagnosed before menarche(35.4%, 17/48), patients diagnosed with diabetes after menarche(18.5%, 10/54) showed significantly less irregular menses(difference 16.9%, P = 0.04). Similarly, compared to patients diagnosed with diabetes prior to menarche(mean age 12.9 years; n = 48), patients diagnosed with diabetes after menarche(meanage 12.26 years; n = 54) were found to have 0.64 years delay in the age of menarche(P = 0.04). Among the studied patients, 15.7%(16/102) had polycystic ovary syndrome(PCOS). Of these PCOS patients, 37.5%(6/16) had irregular menses, 6.3%(1/16) had Celiac disease, 37.5%(6/16) had Hashimoto thyroiditis and 18.7%(3/16) had acne.CONCLUSION More than one fourth of the study population with T1 DM experiencing an irregular menses. Adolescent girls and young women diagnosed with diabetes prior to menarche showed higher menstrual irregularity and a delay in the age of menarche. AIM To identify reproductive disturbances among adolescent girls and young women with type 1 diabetes mellitus (T1 DM) in Saudi Arabia. METHODS This cross sectional study was conducted among 102 female with T1 DM, (aged 13-29 years) who attended the Diabetes Clinic at Diabetes Treatment Center, Prince Sultan Military Medical City, Saudi Arabia between April 2015 and March 2016. Clinical history, anthropometric characteristics and reproductive disturbance were collected through a questionnaire .RESULTS Of 102 patients included in this analysis, 26.5% (27/102) Of these patients, when compared to who diabetes was diagnosed before menarche (35.4%, 17/48), patients diagnosed with diabetes after menarche (18.5%, 10/54) showed significantly less irregular menses (difference 16.9%, P = 0.04), compared to patients diagnosed with diabetes prior to menarche (mean age 12.9 years; n = 48), patients diagnosed with diabetes after menarche Among the patients who had polycystic ovary syndrome (PCOS). Of these patients, anage 12.26 years; n = 54) were found to have 0.64 years delay in the age of menarche (P = 0.04) , 37.5% (6/16) had irregular menses, 6.3% (1/16) had Celiac disease, 37.5% (6/16) had Hashimoto thyroiditis and 18.7% (3/16) had acne. CONCLUSION More than one fourth of the study population with T1 DM experiencing an irregular menses. Adolescent girls and young women diagnosed with diabetes prior to menarche showed higher menstrual irregularity and a delay in the age of menarche.