Mangosteen (Garcinia mangostana L.) generates over 88 billion USD in export revenue to Thailand annually but is restrained due to fruit defects. This study aimed to determine whether smart irrigation with sensors, IoT, and real-time data collection for regulating stable soil water content affects mangosteen fruit quantity and quality. Climate, soil, and mangosteen parameters were compared between irrigated and non-irrigated productions. Flowering and fruit yield data were collected from twenty randomly selected mangosteen trees per irrigation treatment. The results showed that air and soil temperatures were lower, but relative humidity and soil moisture on mangosteen production were greater in irrigated trees than in non-irrigated trees. Irrigated and non-irrigated mangosteen trees showed no significant difference in trunk diameter or crown size. Irrigation boosted mangosteen yields with increased flowers, fruits, and weight but thinner peels, fewer pulp segments, and a higher vulnerability to fruit imperfections. The mean fruit circumference did not differ significantly between non-irrigated and irrigated mangosteen production systems. Mangosteen fruits in irrigated production had fewer fruit defects than those in non-irrigated production. Regulated irrigated mangosteen production with stable soil moisture using soil moisture sensors and IoT produced high-quantity and quality mangosteens with fewer fruit defects. Doi: 10.28991/HEF-2024-05-02-05 Full Text: PDF