Twenty-one new promising lines in addition to four standard cultivars of snap bean (Phaseolus vulgaris L.) were evaluated under eight environmental conditions (four sowing dates in two seasons of 2015/2016 and 2016/2017). A randomized complete block design (RCBD) with three replicates was used for each sowing date at Barrage Horticulture Research Station (BHRS), Qalubia Governorate, Horticulture Research Institute (HRI), Agricultural Research Center (ARC), Egypt. Data were recorded for some traits i.e., number of days to flowering, pod length, pod diameter, fiber content, total green yield and rust disease severity. The results showed that the linear response of environments was highly significant for all studied characters, indicating the differences between environmental conditions and their considerable influence on these traits. Mean squares of genotypes (G) were highly significant for all studied traits, suggesting the presence of wide range of differences between studied genotypes concerning all investigated traits. Mean squares of the other main sources of variation, i.e., years (Y) and sowing dates (D) were also highly significant for all traits except year for total green yield/feddan trait. The mean square due to environment + (Genotypes × Environment) was significant for all studied traits, indicating that there was a considerable interaction of genotypes with environmental condition in different eight environments. Significance of Genotypes × Environment (linear), reveals that genotypes differed in their considerably across different environments. The linear response of environments was highly significant for total green yield trait, indicating that genotypes differed in their regression on the environmental index. The results of stability analysis conclude that the six new lines G1, G2, G3, G7, G10 and G18, were the most stable genotypes, which gave the maximum total green yield overall the eight studied environments and were adapted to environments for total green yield. It is evident that these genotypes could be used as stress tolerant genotypes under stressed environments.