The presence of long-tailed macaques (Macaca fascicularis) in tourism sites such as the Batu Caves results in frequent interactions with a high number of visitors. The survey of current population estimation, nuisance behaviors,and visitor’s perception are important for determining the potential of the Batu Caves as a ecotourism site. The main objectives of this study were to estimate the long-tailed macaque population size in the Batu Caves, identify macaque nuisance behaviors, and determine the visitor’s perception of M. fascicularis. A census walk was performed to know the current population size. A scan sampling technique was used during intensive observation and questionnaire surveys were conducted to evaluate visitor’s perceptions. Four distinct groups of M. fascicularis with a total of 132 individuals were identified in the Batu Caves. Five categories of nuisance behaviors were identified: littering, disturbing visitors, damaging facilities, stealing, and messing up garbage cans. The questionnaire results revealed that local visitors and foreign tourists have different perceptions of the macaques in the Batu Caves. However, the majority of respondents agreed that the Batu Caves have potential as a site for primate tourism. Population censuses and nuisance behavior identification are important for the Batu Caves management authority and the Department of Wildlife and National Parks to improve nuisance management. Our research findings could also assist government and related organizations to develop strategies for improving ecotourism planning and conservation management of M. fascicularis in the Batu Caves.