The observed levels of flavonoid contents confirm the importance of these mangrove plants as excellent sources of plant antioxidants. This study suggests B. gymnorrizha can be a very good source of myricetin. The leaves of K. candel were found to be a rich source of quercetin than the other species under investigation followed by R.mucronata leaves. The presence of luteolin in B. cylindrica alone as well as the variations in different flavonols and flavones in these plants can be helpful for providing chemotaxonomic relationships between different genera of this family. The data presented in this paper offer possible avenues for horticultural approaches towards health promotion by identifying and selecting varieties rich in flavonoids