Primate parasite study is an important subject in primate research, especially with the ongoing threats from anthropogenic disturbances such as land conversion and deforestation. This study is conducted to investigate the occurrence of Cryptosporidium and Giardia in primates of the Lower Kinabatangan Wildlife Sanctuary (LKWS), Sabah, Malaysia. Fecal samples collected were tested with immunochromatographic test kits to rapidly screen for Cryptosporidium spp. and Giardia spp. in samples from 45 long-tailed macaques and 40 proboscis monkeys. The overall rate of infection for Cryptosporidium spp. for both species is moderately high at approximately 44.71% (n = 38), with 17.64% (n = 14) individuals are positive with Giardia spp., while 38.82% of the individuals (n=33) tested are not infected with either Cryptosporidium spp. or Giardia spp. Parasite documentation is an integral aspect of primate research, as the information will provide insights on the health status and disease risk of non-human primate populations, thus helping scientists to make better conservation plans for wildlife.