Terong asam (Solanum ferox L.) has been reported to contain bioactive compounds and functional nutrients such as tocopherol, vitamin C, and antioxidants. This research was aimed to produce fermented drink made from the juice of terong asam. The fermented drink was processed by ratio of water with fruits and addition of skim milk and incubated with Lactobacillus casei. The combination of water and fruit juice were mixed with different ratios of 1:5, 1:4, and 1:3 (w/v).Skim milk was mixed with different concentrations of 0, 2.5, and 5% (w/v) was fermented for 24 hours. Physiochemical properties of the fermented drink includes pH, total titratable acidity, total lactic acid bacteria, total phenolic compound, total flavonoid compound, and antioxidant activity. This study showed that the ratio water: fruits 1:3 and 5% skim consider as the best with total titratable acidity of 0.60%, pH 3.73, total phenolic compound of 15.68 mgGAE/mL, total flavonoid compound of 4.93 mgQE/mL, and IC50 294.47 mg/L. The growth of Lactobacillus casei also was increase to 9.44 log CFU/mL. Storage of fermented terong asam juice drink at 7°C for 4 weeks could stabilize the quality of this drink with total lactic acid bacteria still was 7 log CFU/mL and still accepted by the standard of fermented drink.