Agile mangabeys have a yellowish-gold chest and abdomen. Black mangabeys have pointed crests on the tops of their heads and long, greyish hair on their cheeks. Sooty mangabeys can have pink faces. Gray-cheeked mangabeys have throat sacs, which produce their loud call. The males' sacs are larger than those of the females.
All mangabeys resemble one another in general build and facial characteristics.
Their heads and faces are shorter and rounder than those of macaques. They have white areas above or on top of their eyelids, which are used to embellish facial expressions. All have naked faces and nostrils and cheek pouches. Cercocebus species have shorter hair and coarser fur than the other two species. All have well-developed ischial callosities.