| Abstract | Fifteen rice genotypes including the elite Egyptian rice cultivars were evaluated under twelve divergent environments representing three sowing dates and two plant spacings in 2007 and 2008 seasons. The main objectives were to identify high yielding stable genotypes. Seven characters were number of days to 50% heading, plant height, panicle length, number of grains per panicle, number of panicles per plant, 1000 grain weight and grain yield were studied. The differences between environments, genotypes and the interaction between environments and genotypes were significant or highly significant for most of the studied traits. Delayed sowing date combined with closing plant spacing appeared to be the most favorable environments for early heading and obtaining a short stature plants and the opposite was true for 1000-grain weight and grain yield. Regarding stability analysis, results showed that IET 1444 and Giza 175 were considered the best stable genotypes for heading date. While, Sakha 101 rice cultivar was considered the best stable for panicle length and IR 35366-1-2-3R for number of grains per panicle. Giza 178, Giza 182 and Giza 175 appeared to be the best stable genotypes for grain yield. They had high average performance over the grand mean over environments. Simultaneous considerations of all the parameters X, b, S2d, r2 and ecovalence index (Wi) results showed that Giza 178 was the best stable genotypes for grain yield. Superiority based on 12 environments for Giza 178 ensuring its stability |