One of the assumptions in the scheduling literature is that job processing times are known fixed values. Even though this assumption is true for some manufacturing environments, on the other hand, the assumption does not hold for some other manufacturing environments. Therefore, job processing times should be considered as uncertain variables. In this paper, we address the four-machine flowshop scheduling problem with the objective of minimizing makespan where processing times are uncertain random variables. Since the problem is NP-hard, four heuristics are proposed. Extensive computational experiments are conducted to compare the performances of the proposed heuristics. Computational experiments indicate that one of the heuristics performs very well, and thus, it is recommended.