Ant Colony Optimization is a swarm intelligence approach that has proved to be useful in solving several classes of discrete and continuous optimization problems. One set, called scheduling problems, is extremely important both to academics and to practitioners. This paper describes how the current literature uses the ACO approach to solve scheduling problems. An analysis of the literature allows one to conclude that ACO is a hugely viable approach to solve scheduling problems. On the basis of the literature review, we were not only able to derive certain guidelines for the implementation of ACO algorithms but also to determine possible directions for future research