Image segmentation is a critical task and many algorithms have been proposed in the literature. However, how to select the best technique when facing a real application is still an open issue. A novel method for optimal selection of segmentation algorithms is introduced and an expert system for determining the best algorithms using evaluation results is proposed. The available segmentation algorithms are first evaluated and their characteristics or behaviors in a number of situations are then determined. The determination of the best algorithm is thus based on the knowledge obtained by objective evaluation of available segmentation algorithms. In other words, the algorithm selection is made according to the properties of the algorithms and images to be segmented. Using this idea, a prototype expert system for algorithm selection is designed and implemented. The design considerations and data structure of this system are detailed. Experiments with various real images are carried out and the results indicate that such an idea is feasible and such a system is suitable for practical segmentation applications.