Thirty-four adolescents (ages 12–14 yr) with IDDM completed a questionnaire assessing regimen adherence over the previous week and psychosocial measures potentially related to adherence. Four aspects of the IDDM regimen were studied: insulin injections, dietary patterns, glucose testing, and exercise. Psychosocial variables included (1) Social Learning Theory measures of diabetes-specific family behaviors and barriers to adherence and (2) more general measures of family interaction. Glycosylated hemoglobin levels were predicted accurately (R = 0.68) from a combination of three adherence measures. The psychosocial measures were not directly related to metabolic control, but they were associated with adherence. Degree of adherence to one aspect of the IDDM regimen was not related to adherence to other aspects of the regimen and different psychosocial variables predicted adherence to different regimen components. The diabetes-specific measures were generally more predictive of adherence than were the more global measures. Implications and limitations of this cross-sectional, correlational study were discussed.