Forty-five children aged 6 to 14 years with insulin-dependent diabetes mellitus were recruited from a paediatric diabetic clinic. Glycaemic control, child emotional and behavioural problems, and maternal mental state were assessed at recruitment and after 12 months. Life events were measured at 12 months using a standardised semi-structured interview schedule. A between-groups comparison design was used to explore the effect of life events, child emotional and behavioural problems, and maternal mental state on glycaemic control. The children had relatively high rates of emotional and behavioural problems. Overall, the children had a similar number of life events to healthy children in the general population, but proportionally, experienced fewer desirable events. Children who had experienced at least one event in a family setting, or a disappointing event, were more likely to have high glycated haemoglobin levels afterwards than were children who had not experienced such events. Linear regression models showed that only disappointments, family events and glycated haemoglobin at the start of the study made important independent contributions to glycated haemoglobin at 12 months. Child age, emotional and behavioural problems, and maternal mental state, had no effect on glycaemic control.