The utilization of wild mungbean varieties (Vigna radiata var. sublobata) as a source of bruchid resistance was first started at Chai Nat Field Crops Research Center, Thailand in 1988. TC 1966, an accession of var. sublobata, showed complete resistance against Callosobruchus chinensis and C. maculatus which are the most serious storage pests of mungbean in Thailand. The TC 1966 was crossed with the recommended varieties, Chai Nat 60, Kamphaeng Saen 1 and Kamphaen Saen 2. The bruchid resistance of TC 1966 was controlled by a single dominant gene. After successive generations of backcrossing, the lines obtained displayed a high resistance to both bruchid species. The resistant lines were characterized by a short stature and early maturity in the case of the crossing with Chai Nat 60, an early maturing variety. However, the yield was comparable to that of the best check variety. The bruchid resistance was again re-examined in some selected lines in 1991-1992. Only 34 lines were selected for the preliminary yield trial in the dry season planting of 1993. The seed yield of some of the resistant lines was not significantly different from that of the recommended varieties.