The Korean family planning program began in 1962, originating both in a concern for fmaily well-being and in a concern over a high population growth rate which was cancelling advances in economic capacity, The new program was frank and vigorous in its advocacy of birth control. In recent years, voluntary sterilization as a family planning method has many attributes that cause users of contraceptives to regard it as an ideal method in Korea. A point of these view, author performed a follow-up study on effects of vasectomy and tubal ligation on sociomedical aspects of total 136 men sterilized and 96 women sterilized in SunSan Gun, Kyungpook Province as of Jul6y, 1977. The results were summarized as follows : An average age of vasectomized men was 37.0 and that of tubal ligated women, 34.9. The average duration of marital life was 13.9 years in men sterilized and 14.6 years in women sterilized. An average number of living children at the time of sterilization was 3.6 in men sterilized and that of living children, 3.7 in women sterilized. The most predominant reason for the sterilization was birth control in both (91% in men, 52% in women) and the most common motivating socilitator was family planning field workers (71% in men, 48% in women). About 51 percent of men sterilized and 50 percent of women sterilized were used contraceptive methods before the operation. Experience of induced abortion is reported in 65 percent of wives of men sterilized and 64 percent of women sterilized. In sexual feeling after sterilization, respondents showed increasing coital frequency 21 percent in men sterilized and 10 percent in women sterilized. Sixty-five percent in men sterilized and 64 percent in women sterilized would recommend the operation to others.