The three-parameter lognormal distribution is widely used in hydrology to fit maximum annual flood events. The method most commonly used to estimate the parameters and 7”-year flood event is the method of maximum likelihood. In this paper, Bayes estimates of the parameters and of the 7”-yearflood and their posterior variances of estimates are obtained by using Lindley's Bayesian approximation procedure. These estimates are then compared to estimates obtained by the method of maximum likelihood. Twelve flood series from all over Canada that are shown to be well-fitted by the three-parameter lognormal distribution are used as numerical examples. In all cases the posterior variances of the Bayes estimates of the 7”-year flood events are less than the corresponding variances of their maximum likelihood counterparts.