Experiments were conducted in Kharif season from 1993-1995 to identify a stable high yielding potato genotype under medium and late maturity group for rainfed vertisol conditions. Pooled analysis of variances indicated significant differences among the genotypes environments and genotype X environmental interaction. '85-P-718' was more stable which consistantly showed higher yield while 'JX-118' and 'MS/85-1.63' were adapted to favourable environment under the medium maturity group. In the late maturity group, 'MS/85-163' was found stable but 'Kufri Badshah' was still a best performer. 'JX-115' showed high yield and had the ability to perform well in all the environmental conditions under both the maturity groups.