This study aimed to examine the phytochemical levels of crude “tabon-tabon” (Atuna racemosa Raf.) fruit extracts subjected to air-drying, oven-drying, and freeze-drying. It also sought to validate the claims of previous literature on the fruit’s antimicrobial properties by using its aqueous extracts as an antibacterial wash for green ice leaf lettuce. Phytochemical analysis revealed significantly higher (p < 0.05) levels of alkaloids and tannins compared to coumarins, saponins, and terpenoids. The highest alkaloid content (16.25 ± 1%) was obtained using oven- drying, whereas the highest tannin content was obtained using freeze-drying (14.14 ± 1.13%). In vivo antibacterial assay against Escherichia coli was performed to test the aqueous extracts alongside 200 ppm chlorine solution and water for comparison. Artificially-inoculated lettuce samples were individually soaked in 15-mL solution at 2- and 5-min contact times. Bacterial load was determined at a 2-d interval for a period of 8 d. Results of the microbiological analysis showed no significant interaction in the soaking time used. However, the treatments were independently found to have significant effects on Days 0, 4, and 6. The highest antibacterial effect in green ice lettuce was exhibited up to Day 6.