Crop damage caused by wild Japanese macaques (Macaca fuscata) has been a chronic problem in Kochi Prefecture, western Japan. However, the prefecture has not established a specific management plan for the macaques so far, and each town independently conducts its own countermeasures without a clear objective. I attempted to collect information on the present distribution and dietary habits of the macaques in order to draw up a more effective countermeasure plan to reduce the crop damage. I conducted interview survey about crop-raiding by the macacues and their appearance time to grasp the current distribution and status of the macaques. Based on a discretionary criteria, number of troops was estimated to be 74, and they distributed across the entire prefecture, except for Geisei village. Each troop was composed of 10-30 animals. Troop density was high at 1) mountainous forests in the northern part of the prefecture, and 2) coastal part of Muroto and Hata areas, where home ranges of several troops sometimes overlapped. I also conducted stomach content analyses from captured animals to study their dietary habits. I found that the macaques in Kochi prefecture depended on crops throughout year, while they fed also on natural items in fall. In summary, the present crop damage caused by macaques in the prefecture is fairly light, and therefore performing the basic countermeasure (such as driving them away and setting up fences around crops) should be effective. In areas where the degree of macaque dependence on the cultivated crops is high, on the other hand, we need to capture them. For developing effective countermeasure plans in western Japan, in which information on crop-raiding by macaques has been lacking, each prefecture needs to cooperate more closely to accumulate fundamental information on this matter.