Background: Optimum glycemic control is necessary to reduce and even prevent the risk of micro- and macrovascular complications of type 1 diabetes mellitus (T1DM). The main aim of this study was to assess the prevalence of T1DM patients with adequate glycemic control in 4 Arabian Gulf countries. Methods: This study was a multicenter, observational, cross-sectional disease registry. Data were collected from adult T1DM patients who were treated with insulin within 6 months prior to the study visit. Results: Out of 241 patients whose data were eligible for primary endpoint analysis, 27.4% had adequate glycemic control (HbA1c 7%). The patients’ age ranged from 18 to 64 years, and 53% were males. The mean (SD) duration of diabetes was 14.6 (9) years and the mean HbA1c was 8.11 (1.8) %. At the time of T1DM diagnosis, mean HbA1c was 10.7 (2.17) %. About 98% of the patients were normotensive and the lipid profile of patients was found to be optimal. The main variables associated with adequate glycemic control were low HbA1c at diagnosis (P 0.001) and absence of a family history of diabetes (P = 0.002). Conclusions: We found that the glycemic control of T1DM adult patients in Kuwait, UAE, Oman and Bahrain is suboptimal. More efforts are necessary to pinpoint the causes of inadequate control in this population.