Pasture legume cultivars grown for forage production in the desert environment, suffers a great deal of heat stress. The study was conducted to evaluate forage yield and quality of newly introduced cool-season legumes cultivars under heat stress in the central region of Saudi Arabia for a period of two years. Eight legume cultivars belonging to five species were established during the 2008 and 2009 growing seasons. Cultivars including: two cultivars of red clover (Trifolium pretense L.) (Start and Starfire), three cultivars of white clover (Trifolium repens L.) (Kopu II, Ladino and Alice), and a single cultivars of kura clover (Trifolium ambiguum Bieb.) (Endura), Birdsfoot trefoil (BFT) (Lotus corniculatus L.) (Norcen), and Lucerne (Medicago sativa L.) (Caf 101). Cultivars were evaluated based on plant height, total dry matter yield (DMY) and forage quality. The results showed that red clover, white clover and BFT had greater adaption success and produced higher DMY in the environmental conditions of the central region of Saudi Arabia. Only one species (Kura clover) showed poor establishment during the two years of the evaluation. The two years study proved the superiority of lucerne of its total DMY, thus making it a desirable forage crop for cultivation in Saudi Arabia.