The author has constructed value and, in most cases, price and quantity series for seventeen comparatively homogeneous categories of commodity imports for the peace-time years of the period 1926-1955. These series will be indispensable aids to anyone who wishes to study the behaviour of the Canadian balance of payments in this period.On the basis of these new, disaggregated series, the author has been able to estimate price and income elasticities of demand for individual categories of imports. In contrast with the findings of earlier investigators, who worked with highly aggregative price and quantity series, his estimates of price elasticities turned out in many cases to differ significantly from zero. This suggests that the role of price changes in the balance of payments adjustment mechanism may be greater than earlier studies for Canada and other countries had suggested. The author also has provided evidence of a wartime break in the structure of Canadian import demand; specifically, the postwar price elasticities seem to be significantly smaller than the prewar elasticities.The book will be of interest to all professional economists and to anyone interested in Canadian balance of payments problems.Canadian Studies in Economics, no. 15.