The roof-pond night-cooling technique was investigated for possible use in storage of fruits grown in northern Thailand. A 3 x 3.5 X 2 m experimental test room was constructed and monitored over a one-year period. Two varieties of pear and one variety of persimmon were stored in the cool room during 1983. Results showed that room temperature varied between 9–17°C, and room relative humidity ranged from 85–90%, during the period tested. With 50% good fruits still remaining, the Pien Pu variety of pear could be stored in the cool 'room for 35 days (under normal pressure) and 99 days (under 160 mmHg pressure), compared with 10 days at normal room temperature. The New Century variety of pear could be stored in the cool room for 42 days, compared with 7–10 days at room temperature. For P-1 persimmon, storage in the cool room extended the fruit's life to 119 days (under 160 mmHg pressure), compared to 7 days at normal room temperature, and 7 days in the cool room at normal pressure. These results indicated that the technique has potential, and further investigations are being conducted.