Background The unique and vast pharmacological activities of flavonoids have made them of research interest. This led to the use of various techniques to isolate and characterize them, intending to determine their potential health benefits. Main text The medicinal values of plant-based flavonoids that this literature review tends to summarize the pharmacological activities of these secondary metabolites from 22 selected plant families. The pharmacological shreds of evidence reported in the literature have proven that flavonoids have shown anti-cancer, anti-microbial, anti-oxidant, anti-inflammatory, anti-fungal, anti-ulcer, and anti-edematogenic activities. Out of these, 30% showed to have anti-oxidant activity, key in protecting the body against free radicals. Besides, 18% of the references showed anti-microbial and anti-cancer activities. Further literature reports indicated that flavonoids from these families exhibited anti-inflammatory and anti-edematogenic (9%), anti-viral and anti-ulcer (5%), anti-fungal, anti-nociceptive, and anti-histamine (2%). Conclusion The pharmacological activities of flavonoids from the various sources reviewed in this study show that the secondary metabolites could provide a scaffold for the development of potent anti-cancer drugs in the future.