This report presents the results of accelerated curing of concrete test cylinders using a boiling-water method. Briefly, the method consists of standard moist-curing of test specimens for 24 hours, followed by boiling for 3 1/2 hours and testing for compression one hour later. In all, some 1512 test cylinders, 6 x 12 in., were prepared from concrete samples obtained from three different ready-mix plants (situated in the Montreal-Ottawa area) and a large number of laboratory mixes. The test cylinders were tested in compression at 28 1/2 hours, 7 days, and 28 days. The results were analysed and the advantages and limitations of the method are discussed. The analysis of test data indicates that the relationship between the accelerated- and 28-day standard-cured strengths can be represented by a hyperbolic function of the type Y = X with an accuracy of +- 12 per cent. AX + B The established relationships appear to be independent of the cements, aggregates and admixtures used.