In hydrology, the Box–Cox power normal transformation has been found to perform well in a number of at-site and regional flood frequency studies. In this paper, an alternative to the maximum likelihood method of finding the Box–Cox transformation parameter, λ, is suggested. The proposed method is based on finding the λ that maximizes the correlation coefficient in the probability plot correlation coefficient test for normality. The proposed method of finding λ was tested on maximum daily discharge data from all over Canada and was found to give almost identical results to that obtained by the method of maximum likelihood. The main advantage of the proposed method is that finding the appropriate transformation and objectively testing whether the transformed data are normally distributed can be done in one step. In other methods, at least two steps are required. In addition, the proposed method makes use of techniques that are familiar to the hydrologist, namely, the probability plot and correlation analysis. Key words: flood frequency analysis, Box–Cox transformation, probability plotting, maximum likelihood method, Blom's plotting position, probability plot correlation coefficient test, correlation analysis, normal distribution.