Abstract: The effect of water stress on yield and yield components of two durum wheat varieties was studied at various growth stages, i.e. at vegetative, flowering or grain-filling stage and no stress (control). The decrease in grain yield per plant was more pronounced (72.62 percent) associated with a reduced number of grains per ear (59.62 percent) and 1000-grain weight (31.98 percent) under water stress applied at flowering stage. Stress at grain-filling stage was less effective than at vegetative and flowering stage in both varieties. Variety D-88628 was less affected which showed its adaptability under water stress conditions.