PIP: This is a follow-up study on the efficacy and safety of female tubal sterilization by chemical instillation. A multicenter randomized clinical study was carried out in 1705 eligible women, aged 20-35 years, with identical demographic and gynecological characteristics. They were divided in two groups: 871 using phenol-atabarine paste (PAP) and 834 using phenol mucilage (PM). Results showed that the follow-up rates at the end of 5 years were 97.5% and 98.1%, respectively. Multiple decrement life-table analysis showed that there were significant differences between the two groups in the gross cumulative failure rates in each ordinal month. Moreover, 98.4% of PAP subjects and 96.9% of PM subjects were not found to have suspected cancer cells. No case of psychopathic disease, scleroderma, or psoriasis was reported. Thus, tubal sterilization by the chemical instillation technique proved to be a simple, safe, and efficient method for female sterilization.