Summary: GAO reviewed activities at 15 Professional Standards Review Organizations (PSRO) in 11 States and at the Department of Health, Education, and Welfare (HEW). To date, 37 areas, including the entire States of Texas, Georgia, and Nebraska, have no PSROs. Of the 58 current planning PSROs, 47 were not established until February or March 1977. A number of the 108 conditional PSROs are not performing concurrent reviews at all the hospitals in their areas and have done few or no profile analyses. Some PSROs are or were in the planning stage for what appears to be unnecessarily long periods. Several interrelated factors have impeded implementation of the PSRO program: deficiencies in HEW's program administration; physician opposition; and internal PSRO problems in organizing, developing program plans, converting to conditional status, developing working relationships with State Medicaid and Maternal and Child Health agencies, obtaining support from some hospitals, developing long-term care facility review programs, and coordinating with Health Systems Agencies. HEW failed to promptly effectively organize and adequately staff the PSRO program and obtain or direct cohesive, vigorous efforts among participating branch agencies.