The concepts of risk and uncertainty are commonly utilized for designing and evaluating hydraulic structures such as spillways and dikes. In this study, uncertainty analysis is performed for the risk of failure based on the generalized logistic distribution that is recently recommended as an appropriate probability distribution for flood frequency analysis in UK by Institute of Hydrology. For this purpose, we derived the expected values and the variances of the risk of failure based on the methods of moments, maximum likelihood, and probability weighted moments for the generalized logistic model. The derived variances of the risk of failure based on the methods of moments, maximum likelihood, and probability weighted moments are functions of sample size, design life, and non-exceedance probability. In addition, simulation experiments have been performed to figure out the behavior of the risk of failure for various the sample sizes, design lives, non-exceedance probabilities, and coefficients of variation.