To understand the relationship between pediatricians' personal health and the delivery of pediatric preventive care, Illinois pediatricians were surveyed by mail. Responses from 387 pediatricians (55% response rate) regarding personal characteristics, their practice, and perceptions about preventive care patterns for children aged 2 through 10 years and management of overweight children were analyzed. Overall, 28% of pediatricians were healthy and fit (excellent/very good health and extremely/ very fit), 40% were either healthy or fit, and 33% were neither healthy nor fit. In logistic regression models controlling for personal and practice characteristics, healthy and fit pediatricians (vs neither healthy nor fit pediatricians) more routinely provided recommended care on child diet (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.6-6.2) and physical activity (OR, 3.2; 95% CI, 1.6-6.3) and assessed television time (OR, 4.4; 95% CI, 2.0-10.1). Pediatricians who were either healthy or fit (vs pediatricians who were neither healthy nor fit) more often assessed television time. Therefore, clinician health influenced application of preventive care.