Objective To examine whether friendship and romantic relationships of emerging adults with type 1 diabetes differed from those of a comparison group, and to determine whether these relationships were associated with psychological and diabetes health outcomes. Methods High school seniors with (n = 122) and without (n = 118) type 1 diabetes were assessed annually for 3 years. Friend and romantic relationship variables, psychological distress, life satisfaction, eating disturbances, and, for those with diabetes, diabetes outcomes were assessed. Results Those with diabetes reported less friend support but similar friend conflict compared with controls. Aspects of romantic relationships and friend relationships were associated with health outcomes, but there were more effects involving romantic relationships. On some indices, romantic support was more beneficial for controls and romantic conflict was more troublesome for those with diabetes. Conclusions Both friendship and romantic relationships were associated with psychological and diabetes outcomes among emerging adults.