The aim of this investigation was to determine the contributions of coping behaviors used at diagnosis to medical (metabolic control) and psychosocial adjustment (self-perceived competence; adjustment) 1 year later. A total of 89 children (8 to 14 years of age; 48% male; 59% White) received follow-up quarterly from diabetes diagnosis to 1 year later. Findings indicated that, in general, although metabolic control worsened over the first year, psychosocial status and coping behaviors were stable. Boys had worse metabolic control than girls. Multiple regression analysis indicated that self-worth at 1 year postdiagnosis was associated with less use of spirituality (beta = -.44), more use of humor (beta = .28), and more positive self-care (beta = .28); and self-care was less likely to be positive in older children (r = .32). These variables accounted for 47% of the variance (39% adjusted) in general self-worth when entry self-worth was controlled. Poorer overall adjustment at 1 year postdiagnosis was associated with more use of avoidance behaviors (beta = -.47) and poorer self-care (beta = -.71); and more use of avoidance was associated with older age. These variables accounted for 62% of the variance (58% adjusted) in adjustment when adjustment at diagnosis was controlled. Poorer metabolic control was associated with more use of avoidance (beta = .30) and female gender (beta = .39), and avoidance behaviors were more common in older children (beta = .12). This model predicted 33% of the variance (25% adjusted) in metabolic control 1 year after diagnosis.