This study evaluates a mandatory second-opinion consultation program administered on behalf of a large Taft-Hartley welfare fund providing medical care coverage for 120,000 beneficiaries and covered dependents. During a two-year intake period (1977-1978), 2,284 individuals received second-opinion consultations for an elective surgical procedure recommended by a first-contact physician or surgeon. Of this group, 366 received a nonconfirmation of their need for surgery. Medical claims data were available for 342 individuals in this group, and they constitute the base for the current analysis. A comparable number of individuals who received a positive confirmation were randomly selected and served as a control for estimating program savings. Both groups were followed for a one-year period from the date of their consultations. Total program savings were estimated at $534,791. Of this amount, medical care utilization savings were $361,756 and productivity savings were $173,035. The cost of the program was $203,300, yielding a benefit—cost ratio of 2.63. These findings indicate that mandatory second-opinion consultation programs, which are consumer oriented and intervene before care is rendered, are clearly cost-effective.