Techniques used in computer graphics and pattern analysis have been applied to the tasks of observing, classifying, and recording spontaneous behavioral activities in the captive primate. The goal in designing this system was to provide a computer-based pattern recognition system capable of identifying normal activity patterns of the primate Macaca fascicularis. If successful, this system can be used to detect alterations in these patterns under conditions of toxicologic and pharmacologic insult. In this article, the development of the system, which is called PROBE (pattern recognition of behavioral events), is discussed. Throughout this project, the purpose was to solve a unique application problem. Existing pattern recognition methods consistent with the adequate solution of the problem, were applied.