More than 1.1 million people were employed in out-of-home child care facilities in the United States in 1998, and this number is expected to increase over the next 10 years. This group consists primarily of women with a median age of 35. This review of the literature provides convincing evidence that these women have an excess risk of infection with a number of diseases, including cytomegalovirus, parvovirus B19, and, possibly, giardia. These workers also face an epidemic risk of such other infections as shigellosis, hepatitis A, and cryptosporidiosis. Handwashing, good hygiene, and, where indicated, immunization, remain the mainstays of prevention for this group.