The similarity equations for mixed-convection boundary-layer flow past a wedge having one of its surfaces parallel to the horizontal are derived for the latter surface. Both cases of prescribed wall temperature and heat flux are considered. It is shown that non-unique solutions exist for aiding (α > 0) as well as opposing flows (α < 0); α being the buoyancy parameter. In some situations there are four simultaneous solutions. Dual solutions for two previously studied mixed-convection boundary-layer flows are shown to exist for α > 0 in addition to those already reported in the literature for α < 0. Namely, these correspond to vertical flat plate and vertical cylinder problems.