Comparative status of foliar photosynthetic pigments, nutrients, polyphenol, flavonoids, and antioxidant activities of Vitex negundo L. were studied in three different growing seasons within a generation. An experiment was managed during February, 2019 to January, 2020 at the Botanical Garden, University of Chittagong. Maximum foliar photosynthetic pigments, nutrients were assessed in monsoon (June-August) and minimum in late monsoon (September-November) respectively. Meanwhile the highest flavonoids content was observed in the leaf extract of early monsoon (March-May) and the lowest in late monsoon (September-November) respectively. Moreover the maximum polyphenol and antioxidant activity were estimated in the leaf extract of late monsoon (September-November) and the lowest in early monsoon (March-May) respectively. Present study concludes that monsoon (June-August) is competent for efficient photosynthesis as well as nutrient assemblage in Vitex and early monsoon (March-May) is for flavonoid synthesis and late monsoon (September-November) is suitable for collecting leaves of Vitex to be acquired highest antioxidant activity and polyphenol content for medicinal use.