Barley ( Hordeum vulgare
L.) is one of the founder crops of the old world agriculture and was one of the first domesticated cereals. The objective of this study was to estimate the magnitude of genotype x environment interaction and stability for barley grain yield and yield related traits in the growing areas of Tigray. Eight nationally released varieties, together with four farmers’ varieties, were planted in randomised complete block design, with three replications. The additive main effects and multiplicative interaction analysis of grain yield showed that environment, and GEI were highly significant (P<0.01), whereas variations due to genotypes were not significant. They accounted for 72.21, 9.16, and 4.47% of the total sum of squares, respectively. Large sum of squares indicated that the environments were diverse; causing most of the variation in grain yield. The multiplicative variance of the treatment sum of squares due to GEI was partitioned into the interaction principal component axes IPCA1, IPCA2 and IPCA3, which explained 58.06, 27.11 and 14.82% of the interaction sum of squares, respectively; but only the IPCA1 was highly significant. Atena, Shediho, Basso and Agegnehu with a lower IPCA1 score, were stable genotypes; whereas HB-1307, Estayish, Himbilil and Yidogit with relatively higher IPCA1 scores were unstable genotypes. The same was observed in ASV as AMMI stability. Maychew, with a low IPCA value was favourable environment for all genotypes; whereas Korem with a high IPCA score was unfavourable one.