Abstract: This study was undertaken with the aim of elucidating the role that imbibition process play in causing poor germination of seeds of two underutilized legumes and whether scarification could improve germination percentage. Twenty individual seeds were placed in numbered positions in a germination tray and used to monitor the imbibition process. Similarly, another set of seeds were used for standard germination tests in moist sand as a control for scarified seeds that were tested both in sand and paper substrata. The phases I and II of imbibition lasted 4 and 18 h in pigeon pea and 6 and 24 h in African yam bean, respectively. Threshold water content for germination was 127.47 and 80.84% respectively for pigeon pea and African yam bean seeds despite that African yam bean seeds were about 2.5 times bigger than pigeon pea seeds. In sand substratum, scarified seeds imbibed significantly (p<0.05) more water compared with intact seeds in both species. Increase in weight of scarified seeds as a result of imbibition in paper substratum was significantly less than in sand substratum, by 52.32% in pigeon pea and 20.05% in African yam bean. However, relative to intact seeds, germination percentage of scarified seeds was reduced respectively by 13.86 and 29.70%. Similarly, germination of scarified seeds in sand substratum was reduced by 15.83% in pigeon pea and 27.64% in African yam bean compared with paper substratum. Therefore, rapid imbibition was a cause of reduced germination and scarification is not necessary for both species as it accelerated imbibition.