We reviewed results of the first 131 recipients who received a single or bilateral sequential lung transplant at Barnes Hospital between July 1, 1988, and July 31, 1992. Follow-up data were complete as of January 1, 1993, for a minimum of 5 months' follow-up for all surviving recipients. There were 11 hospital deaths for an overall 92% hospital survival. Thirteen late deaths occurred and 107 (81%) recipients remain alive with a median follow-up period of 19 months. One hundred nineteen recipients survived at least 3 months after transplantation, and for this group factors that might influence long-term results were evaluated. The prevalence of pathologically proved bronchiolitis obliterans was 18.5%. Functional deterioration, which may not correlate with pathologic findings, was evaluated with a recently developed bronchiolitis obliterans syndrome staging system. Factors not influencing long-term outcome included the number of early rejection episodes, matching donor and recipient cytomegalovirus antibody status, or underlying diagnosis. Patients undergoing single lung transplantation for primary pulmonary hypertension or Eisenmenger's syndrome had results similar to those of other diagnostic groups. Furthermore, the hemodynamic improvement previously reported for this group of patients after single lung transplantation has been maintained at long-term follow-up. The shortage of donor organs and the need for improved methods for diagnosis and management of chronic rejection remain the most challenging problems in lung transplantation.