Due to normal variations in dimensions inherent in the manufacture of the components of a mechanism, there is a small probability of not meeting the accuracy predicted by a deterministic representation of the mechanism. The reliability of a mechanism can be defined as the probability of deviation from its specified function. This paper presents a Monte Carlo simulation approach for the reliability analysis of function generating mechanisms. The approach is illustrated by considering the reliability analysis of a four-bar straight-line mechanism. The effect of the probability distribution of the random parameters on the overall reliability is also investigated. The Monte Carlo approach can be coupled with the known statistical properties of the production techniques to significantly increase the production yield of mechanisms that satisfy specified reliability requirements.