Abstract: Superior grain yield across environment is the main goal of teff breeders. The genotype by environment (G x E) interaction influence on grain yield, plant height and shoot biomass were analyzed by application of ANOVA. The objective of this study was to compare the means of teff genotypes tested in an experiment and to identify the effect of genotypes and environment on teff production. Data for this study comprised of 18 teff genotypes grown in twelve locations (environment) obtained from Debre Zeit teff research program.