Abstract. Background. After-hours telephone calls are a stressful and frustrating aspect of pediatric practice. At the request of private practice pediatricians in Denver, a metropolitan area-wide system was created to manage after-hours pediatric telephone calls and after-hours patient care. This system, the After-Hours Program (AHP), uses specially trained pediatric nurses with standardized protocols to provide after-hours telephone triage and advice for the patients of 92 Denver pediatricians, representing 56 practices. Objectives. This report describes the AHP, presents data from 4 years' experience with the program, and describes results of our evaluation of the following aspects of the program: subscribing physician satisfaction, parent satisfaction, the accuracy and appropriateness of telephone triage, and program costs. Methods. After-Hours Program records (including quality assurance data) for all 4 years of operation were retrospectively reviewed, tabulated, and analyzed. The results of two subscribing physician surveys and one parent caller satisfaction survey are presented. A retrospective review of after-hours patient care encounter forms assessed the necessity for after-hours visits triaged by the AHP. An analysis of the total cost of this program to 10 randomly selected subscribing physicians was conducted using current AHP data and a survey of the 10 physicians. Results. In 4 years, 107 938 calls have been successfully managed without an adverse clinical outcome. Minor errors in using protocols occurred in one call out of 1450 after-hours calls. After-hours phone calls necessitated an after-hours patient visit 20% of the time and generated one... [ABSTRACT FROM AUTHOR]