Genotype-environment interactions for yield, final height and days to maturity were analysed by means of statistical and genetic techniques in five cultivars of durum wheat (Triticum durumDesf.) grown for 4–5 years in 5 locations in Western Canada. Differences in the response to environment were found among genotypes for the characters studied. A significant proportion of the genotype-environmental interaction component of variation proved linearly related to the additive environmental component in two and in three cultivars and as well as in one for yield, height and days to maturity, respectively. Sensitivity to environment, as measured by the linear regression, was correlated with mean performance only in the case of height. There was a significant positive correlation between height and yield.