Head and body length is up to 764 mm and tail length is 25 percent of that. The body is generally stout and the limbs are strong. Macaques have been found to breed between the species without any compromise to the offspring's fertility. M. nemistrina is found in inland tropical broad leaved evergreen forests. Group sizes vary depending on whether or not the habitat has been disturbed; in areas that have not been disturbed, group sizes can range from 30-47 individuals, whereas they drop to between 3-15 in areas which have been disturbed.

Gestation last from 162-186 days, resulting in the birth of most often one, but sometimes two, offspring. Birthweight is about 453 grams. The infant will nurse for about 1 year, first clinging to its mother's belly, and later riding on her back. Sexual maturity is reached at 2.5-4 years in females and about 2 or 3 years later in males.

M. nemistrina is often caught by humans and taught to harvest coconuts, and is used for food and the medicinal properties of its flesh.

M. nemistrina is found in the Malay Peninsula, Borneo, Sumatra and Bangka Isl (Indonesia), Thailand north to about 7º30'N.