Five species of non-human primates occur in Sri Lanka—the toque macaque (Macaca sinica), purple-faced langur (Trachypithecus vetulus), slender lorises (Loris tardigradus and Loris lydekkarianus) and the gray langur (Semnopithecus priam thersites). The primates of Sri Lanka are endemic and considered to be Critically Endangered or Endangered. Here we report on some observations, information from interviews with local people regarding primate-human interactions, and also morphological differences in the subspecies we observed during field visits in 2004, 2005, and 2007. When asked, most people stated that they believed that primate populations had increased over the years, and many consider them to be agricultural pests due to the damage they inflict on crops. Due to religious beliefs, hunting and killing of primates were reported in low frequency, but some eat the meat of purple-faced langur for medicinal purposes. The most common methods people use to prevent monkeys from damaging crops are throwing stones, and the use of firecrackers or any other way of producing loud noises. The major threat that these primates face is the destruction of their habitat due to deforestation, human population growth and the expansion of various rural development projects. Public awareness programs for schools and through the media are needed to encourage the protection of these animals and their habitats.