Research on the association between health locus of control and depression in chronic illness has produced contradictory findings, perhaps because of a failure to consider contextual variables. In this study of 96 hemodialysis patients, the belief that one's health is controllable was associated with less depression among Ss who had not previously experienced a failed renal transplant. This belief was associated with greater depression for Ss who had returned to dialysis following an unsuccessful transplant. This interactive effect occurred among severely ill Ss, but health locus of control was unrelated to depression among Ss with less severe disease. This pattern occurred both when control perceptions reflected a belief in the Ss' own or powerful others' (i.e., health care providers) ability to influence health outcomes. Results underscore the adaptive value of congruence between control beliefs and objective circumstances in chronic illness.