We analyzed factors affecting the length of hospital stay for tubal sterilization in 1970 and 1975, using data from the National Center for Health Statistic's Hospital Discharge Survey. The average hospital stay for tubal sterilization declined from 6.5 nights in 1970 to 4.0 nights in 1975. Pregnancy status, region of residence, and race were important determinants of the length of hospital stay. One technological innovation, the use of the laparoscope for tubal sterilization, accounted for 39% of the total length-of-stay reduction from 1970 to 1975. General changes in medical care from 1970 to 1975, combined with the introduction of laparoscopy, averted 1,363,000 nights of hospitalization for tubal sterilization in 1975. Conservatively, this resulted in a savings of more than $200 million. About $80 million of this savings was directly attributable to laparoscopy. Even greater savings could have been achieved if sterilization techniques requiring shorter hospital stays had been more widely used.