Type 1 diabetes (T1D) is the most common form of diabetes in children in Western countries. There have been no large studies of childhood diabetes from India. We undertook the MEDI study (Multicenter Survey of Early Onset Diabetes in India) to assess the proportion of various subtypes of diabetes among the young subjects presenting to the endocrinology divisions of seven large teaching hospitals in different regions of India. In addition, we compared the clinical features of T1D and type 2 diabetes (T2D) in Indian subjects. Patients with onset of disease at younger than 20 years of age were included in this study. Six hundred and three subjects (603) were studied of whom 535 subjects (89%) had T1D, 36 (6%) had T2D, 18 (3%) had diabetes related to tropical pancreatitis or other forms of chronic pancreatitis, while other subtypes accounted for the rest. Compared to those with T2D, subjects with T1D were younger, had a lower C-peptide level, higher prevalence of ketosis, lower prevalence of acanthosis nigricans, and lower LDL and triglyceride levels. When compared with that of T2D, a higher proportion of patients with T1D were positive for GAD-65 and IA-2 antibodies, and this difference was statistically significant for GAD-65 antibodies. Overall, this large multicenter study showed that T1D is the commonest form of diabetes in childhood. T2D is the next most common kind, while chronic pancreatitis-related diabetes is uncommon.