We examined family composition as it related to health status, health behaviors, and psychosocial functioning of 119 adolescents with type I diabetes mellitus (DM1). Findings revealed that adolescents with DM1 from intact (INT), single-parent (SP), and blended (BLND) families did not differ on measures of adjustment to diabetes and adherence to treatment. Adolescents and their parent(s) from INT, SP, and BLND families also did not differ on measures of general or issue-specific parent-teen conflict, communication skills deficits, overt conflict, extreme beliefs or functional/structural family problems. Combining INT and BLND family data revealed that adolescents from two-parent (TP) families were in significantly better metabolic control than adolescents from SP families. Because African-Americans adolescents were more likely to reside in SP homes, race was taken into account when analyzing the relation between metabolic control and family composition. Results revealed that African-American adolescents from SP families were in poorer metabolic control than African-American adolescents from TP families, and Caucasian adolescents from both TP and SP families. The findings from this study suggest that family composition is likely to be too broad of an issue in predicting health outcomes for adolescents with diabetes; and instead more specific family factors should be the focus of future research.