The purpose of the present study was to determine the cumulative probability of the first diabetes-related rehospitalization within the initial 2.5 years after the onset of insulin-dependent diabetes mellitus (IDDM) among newly diagnosed children, and to identify risk factors that can be determined shortly after IDDM-onset. The sample consisted of 88 children, 8 to 13 years old at the onset of IDDM, who had been participating in a longitudinal study. In this sample, there was a 0.25 cumulative probability of an early readmission. Poor control was the most frequent reason for readmissions. Four variables significantly increased the risk of early rehospitalization: severity of child's externalizing symptoms at IDDM-onset, lower socio-economic status, younger age at onset of IDDM, and higher levels of glycosylated haemoglobin, reflecting poorer metabolic control. Because externalizing symptoms and poor control are amenable to change, some early rehospitalizations can potentially be prevented. Furthermore, information about the risk of early rehospitalization should be part of initial diabetes education in order to better prepare families for the possibility of such an event.