Children at summer camp are at risk of injury and illness. The American Academy of Pediatrics and the American Camping Association have specific guidelines for the medical care of children in summer residential camps. This report describes the types of illnesses and injuries seen in 730 children attending camp for 2 weeks, use of the infirmary, and difference in the onset of infectious diseases compared with injuries during the camp session. During the month studied, there were 921 infirmary visits. The most common diagnoses were injuries and infectious disease. Girls and boys were equally likely to be seen in the infirmary and had the same distribution of diagnoses. Infectious disease (gastroenteritis) had a later mean day of onset during the camp session than did injuries and was increasing in frequency at the end of each session. Potential common camp medical problems (sunburn, otitis externa) were prevented by simple medical preventive care.