Abstract : Ascorbic acid and flavonoids are key antioxidants widely recognized for their therapeutic potential in preventing oxidative stress-related disorders such as cardiovascular disease, neurodegeneration, and cancer. These compounds modulate inflammation, neutralize reactive oxygen species (ROS), and support tissue regeneration, immune function, and cellular protection. Salak pondoh as one of a tropical fruit native to Indonesia, is rich in both antioxidants yet remains underexplored in postharvest medical-nutritional research. Its rapid perishability limits its broader application as a functional food or medicinal dietary source. This study evaluated the effects of besek (bamboo) packaging and storage temperature (10–15°C and 33°C) on the retention of ascorbic acid and flavonoids, using spectrophotometry. The experiment was conducted in four replicates over 12 and 24 days. Data were analyzed using ANOVA and Tukey’s HSD test. Storage temperature significantly affected ascorbic acid levels (p<0.05), while packaging did not (p>0.05). Fruits stored at low temperatures retained higher ascorbic acid levels (1.45 mg/100 g on average) than those at room temperature (1.18 mg/100 g). The P1T1 treatment (packaged, low temperature) recorded the highest ascorbic acid content on Day 24 (1.80 ± 0.94 mg/100 g), a 42.86% increase over P1T0 and P0T1. Although flavonoid differences were not statistically significant (p > 0.05), P1T1 consistently maintained the highest levels—3.85 ± 0.44 mg QE/100 g on Day-12, and 3.07 ± 0.97 mg QE/100 g on Day-24 representing a 24.29% and 24.09% increase over P1T0 and P0T1, respectively. These findings highlight salak pondoh’s potential as a postharvest-preserved source of bioactive antioxidants. Combining low-temperature storage with besek packaging effectively maintains its nutritional and therapeutic value, supporting future applications in medical nutrition and functional food development.