A total of 16 accessions of Yam Bean (14 Pachvrhizus erosus. 1 £. ahipa and 1 P. tuberosus) were tested in a yield trial in Tonga. In addition 29 other accessions representing four different species of-Yam Bean (24 P. erosus. 2 P. ahipa. 2 P. tuberosus and 1 P. panamensis) were observed in multiplication plots. In the yield trials fresh weight tuber yields were up to 72 tons/ha. Dry matter percentages ranged from 8.0 to 20.8 with dry matter yields ranging from 1,13 0 Kg/ha to 7,4 60 Kg/ha. Nitrogen contents of raw peeled tubers were between 0.82 to 1.57% giving crude protein yields of 71-540 Kg/ha, or about twice as much as sweet potatoes (Ipomoea spp.) when grown under similar conditions in Tonga.