Abstract The existing Superpave method of evaluating moisture susceptibility is deterministic, relying only on the mean values. This technical note presents a new method for evaluating moisture susceptibility considering uncertainty. The method considers the uncertainties of the four measured properties (thickness and maximum load) of conditioned and unconditioned specimens in formulating the uncertainty of the tensile strength ratio (TSR). The probability distribution of TSR is established based on a normality assumption that is verified using Monte Carlo simulation. A simple formula is developed for checking whether the TSR criterion is satisfied, given a specified confidence level. Another formula that incorporates the uncertainty of the TSR criterion is also presented. The proposed method directly considers the uncertainties of the actual test variables and as such takes the current indirect National Cooperative Highway Research Program method of interlaboratory precision estimates one step further.