Two field experiments were carried out to evaluate and estimate the stability of fifteen faba bean genotypes at two different locations; Sids Research Station in upper Egypt and Sakha Research Station in Lower Egypt, during the two growing seasons 2009/2010 and 2010/2011 in three dates 15 October, 1st November, and 15 November. A split plot design with three replications in a randomized complete block arrangement was used in both locations. Planting dates were randomly arranged to the main plot, while the fifteen faba bean genotypes were distributed in the sub plots. Statistical analysis for split plot design was separately carried out for each year as well as combined analysis over two years in each location and the combined data of the two experiments in the two locations were performed . The data were analyzed by Eberhart and Russell (1966) and Tai (1971) procedures to estimate phenotypic and genotypic stability parameters for seed yield . The results could be summarized as follows : 1-     The results indicated that there was wide range for the environmental index ( - 2.59 to +4.02) which indicates that there was differences among the different environmental condition . 2-     Highly significant environment (linear) mean squares indicating that environments differ in their effect on different genotypes. 3-     The analysis of genotypic stability indicated that both of the linear regression variance and the deviation variances from linearity (non-linear ) were highly significant where the main component of the stability differences was due to the linear regression by 92.3 %  from the total variance 4-     Highest yield /fed was given by genotype Sakha 3 being 10.38 ardab/fed followed by genotypes  H 943  , Giza 3 and Sakha 1 that produced 10.29 , 9.83 and 9.77 ardab/fed. respectively. 5-     Eberhart and Russell method showed that genotypes Sakha 3 , Misr 1 , Nubaria 1 and Giza 2 had phenotypic stability and stable performance in the environments which had b_i not significant different from unit and insignificant deviation from linearity . 6-     Tai′s parameter α and λ showed that genotypes Giza 40 and Giza 2 exhibited above average stability (α < 0 and λ ≈ 1) while , the genotypes Sakha 3 and Misr 1 had a degree of below average stability (α > 0 andλ = 1 ) .