Two-hundred-twenty-two pediatricians were surveyed to determine the use of developmental screening tests in primary-care pediatrics. Sixty-three percent of the 121 primary care pediatricians responding to this survey reported that they use developmental screening tests, but only 15 to 20% screen more than 10% of their patients with these tests. Factors associated with the use of developmental screening tests included the year of graduation from medical school, level of postinternship training, duration of current practice, training in the use of tests as a house officer or fellow or at postgraduate seminars, and belief that the use of developmental screening is a necessary part of routine health maintenance. Pediatricians use developmental screening tests infrequently and, probably, only after evidence of developmental delay has been established by other criteria.