Interest in commercial production of soursop has increased recently in several countries of Tropical America. The work presented here deals with some aspects of the practice of defoliation and its relation to flowering and fruit production of soursop. Treatments used to evaluate defoliation were 1) control; 2) defoliation by hand; 3) potassium iodide at 1.5%; 4) Ethrel at 1500 mg/1; and 5) Ethrel at 2,000 mg/1. The sum of the growth of new lateral branches was significantly superior in all treatments compared to that of the control, with approximately 100 cm of new growth 9 months after treatment. Defoliation by hand and with Ethrel at 1500 and 200 mg/1 shifted formation of new flowers toward the region near the apex of branches. Total flower number 9 months after treatment was statistically superior in the treatments of defoliation by hand and by 1,500 mg/1 Ethrel, with 362 and 370 flowers, respectively. Total fruit production per year was significantly greater in the 1.5% potassium iodide treatment with 21 fruits/trees and a fruit weight at 15.27 kg.