Objective: To determine the influence of previous infectious illnesses and health care coverage on the utilization of health care services for young children. Study Population: Children aged 6 weeks to 5 years who received health care at a large pediatric practice in Norfolk and Chesapeake, VA enrolled between 3/96 and 11/97 into an ongoing 3-year surveillance study. Methods: At enrollment, parents completed an oral survey concerning their knowledge, attitudes, and practices regarding infectious illnesses and health care utilization. Parents were questioned regarding previous experience and anticipated utilizations. Results: The 517 children were 52% male and 81% white. The mean age was 22 ± 1 mo. Parents reported that children had a median of 1 visit (range 0-25) to the physician for upper respiratory symptoms in 6 mos prior to the survey. In order to visit the physician, 49% of parents would miss work. Children previously diagnosed with otitis media (OM) were more likely to visit the physician for ear pain (326/329) than children without a previous OM (173/181)(OR=5.03; 95% CI, 1.2-29.7). All 44 children previously diagnosed with Group A Streptococcus (GAS) pharyngitis were more likely to visit the physician for sore throat than children without a previous GAS pharyngitis (370/433)(p=.007). Children previously diagnosed with “cold” (211/363) were less likely to visit the physician for future cold symptoms than children without a previous diagnosis of “cold” (103/152) (OR=0.66; 95% CI, 0.43-1.00). Previous diagnoses of bronchitis and pneumonia did not influence anticipated health care utilization for cough. The level of parental education did not influence anticipated health care utilization for upper respiratory symptoms. In this study, 495/517 (96%) families reported third party health care coverage. Families covered by HMO, Medicaid, and CHAMPUS tended to visit a physician more often for rhinorrhea and cold symptoms (p=.08) than PPO, private insurance, and self-pay families. Conclusions: Previous diagnoses of OM and GAS pharyngitis were the most important predictors of parental behavior for increased health care utilization in this survey. Previous experience with “cold” resulted in fewer visits to the physician. These findings will guide efforts to educate parents for appropriate health care utilization in a private practice setting.