Some species in Vicia sativa complex, also called aggregate (C-VS), have economic and ecological advantages and they are frequently used for pasture, silage, and green manure. The main objective of this study was to explore the secondary gene pool for enhancement of common vetch (Vicia sativa L.) germplasm by genome introgressions via conventional crosses made between cultivated common vetch (Vicia sativa L. subspecies sativa) used as female parent with five other subspecies [amphicarpa (L.), Batt., cordata (Wulfen ex Hoppe) Asch. & Graebner, macrocarpa (Moris) Arcang., nigra (L.) Ehrh., and segetalis (Thuill.)], used as male parents. As indicated with very low seed sets, higher levels of sterility were the rule in hybrids in C-VS. Hybrids were confirmed using flower petal color and anthocyanin pigmentation markers. Chromosome count studies revealed that certain crossing-experiments were successfully produced interspecific hybrids. Certain offspring progenies in further generations were also obtained. Our studies clearly indicated that complex C-VS and hybrids obtained from these species consisted of 10, 11, 12, 13 and 14 pair of somatic chromosomes. Results indicated that there exist significant incompatibility alleles possibly expressing in the zygote or post-zygotic developmental stages within the C-VS. In conclusion, present study revealed that sufficient amount of seeds could be obtained from the crosses in the C-VS and this stimulates renewed interest in utilizing the secondary gene pool as a source of genetic variation in breeding programs of common vetch.