The sources of the randomness in creep and shrinkage are basically three: (a) random variation of material parameters; (b) uncertainties of the creep and shrinkage models; and (c) influence of the random variation of environmental humidity and temperature. The purpose of this paper is to solve the random shrinkage stress problem with all three sources of randomness taken into account. The random variables in source (a) are considered as correlated, those of source (b) as independent random variables, and those of source (c) as stochastic processes which can be determined by spectral analysis of real humidity records. For the sake of simplicity, all of the system equations are assumed to be linear. A numerical example is given and a simplified expression for predicting the confidence band of response is developed.