The adult red-shanked douc is about 61–76 cm tall, and its tail is about 56–76 cm long. It weighs about 8–11 kg. Red-shanked doucs have black hind legs that are red from knee to ankle. They have white hips, tails and forearms, and reddish yellow faces. They have red and black stripes over their eyes. Male red-shanked doucs have white scrotums, red penises and white patches on their bottoms. This makes it easy for humans to tell male and female red-shanked doucs apart.