The aims of this study were to evaluate short-term changes in retinopathy in adolescents, and to examine the relationship of these changes to risk factors. Two-hundred and three adolescents, with a median age of 14.5 (range 10.4 to 20.6) yr and a median duration of diabetes of 6.6 (1.1 to 16.3) yr, were included in the study. Retinopathy was assessed on two occasions, using stereoscopic fundus photography; the median time between assessment was 1.3 (0.5 to 3.0) yr. At baseline, 41% of the adolescents had background retinopathy. When patients were stratified according to the median diabetes duration (DD) (6.6 yr) and glycaemic control over the 12 months prior to assessment (HbA1C) (8.4%), the percentage of retinopathy in each group was: lowDD/lowHbA1C 13%; lowDD/highHbA1C 40%; highDD/lowHbA1C 42%; and highDD/highHbA1C 72%. Using a 2-step criteria for stability or change in retinopathy, 11% of the 203 adolescents showed progression of retinopathy, 41% had stable retinopathy, 5% showed regression, and 43% had no retinopathy at either assessment. Change in retinopathy was related to age at baseline assessment (borderline significance, p = 0.06), diabetes duration (p < 0.001), glycaemic control (p < 0.001) and total cholesterol (p = 0.04), and was also related to DD/HbA1C group membership (chi 2, p < 0.001). This study highlights the combined adverse effect of long diabetes duration and poor glycaemic control on the development and progression of retinopathy during adolescence, and identifies a group that is likely to show progression over a relatively short period.