The present study was aimed at evaluation of the potential usefulness of oilseeds and byproducts (cakes) of Balanites aegyptiaca, Detarium microcarpum, Vangueria madagascariensis and Ziziphus spina-christi as source of antioxidants and enzyme inhibitors. Results showed that the cakes contained higher amount of total phenolic and flavonoids than the oils. Online HPLC-antioxidant assays revealed that in all cake extracts, pelargonidin was the major contributor to the Fe+++ reducing capacity while rutin was the principal contributor in other systems. Cake of D. microcarpum exerted the highest scavenging radical and ions reducing properties. The metal chelating power was only exerted by the oil of Z. spina-christi. All oils and cake extracts displayed considerable acetylcholinesterase, butyrylcholinesterase and α-glucosidase inhibitory activity. The tyrosinase inhibitory activity was mainly displayed by cake extracts. In conclusion these findings suggested that the oils and cakes of these underutilized plants can be used in different food, pharmaceutical and cosmetic applications.