Applied structural equation modeling to a longitudinal data set of 193 youngsters with insulin-dependent diabetes mellitus assessed on two occasions, an average of 1.65 years apart. Six adherence constructs, Injection, Exercise, Diet Type, Testing-Eating Frequency, Calories Consumed, and Concentrated Sweets, were quantified from 24-hr recall interviews conducted with mother and child. Glycemic control was indexed by glycosylated hemoglobin (HA1C); lipid metabolism was indexed by fasting triglyceride levels (TRIG). The relationship of each adherence construct to metabolic control was tested separately. Patient age and disease duration served as exogenous variables in all models. Testing-Eating Frequency was associated with HA1C and Injection was associated with TRIG; in both cases better adherence was associated with better metabolic control. However, the standardized regression weights and variance accounted for were small. Patient age was a predictor of both adherence and metabolic control; older youngsters were less adherent and were in worse metabolic control. In spection of models for younger versus older children suggested that age-homogeneous models improved prediction, but adherence and metabolic control linkages remained weak. Suggestions for refining the model are provided.