Families bringing children to the pediatric walk-in clinic at Boston City Hospital were interviewed randomly over a 15-week period. Families were classified as having a stable or unstable relationship with either a hospital or a neighborhood health center (NHC) from their answers to a structured questionnaire. Little change was found in the proportion of unstable users of health facilities from a similar study conducted in 1964, suggesting that the introduction of the NHCs and Medicaid, which increased the availability and accessibility of health services for the urban poor, has no effect on patterns of multiple utilization of health providers. The major variables affecting a family's utilization pattern are hypothesized to be the level of satisfaction toward the primary care facility, as expressed by the family, and the perceived ability of different health care facilities to deal with a particular health situation.