The Ln(B0.5Mn0.5)O-3 (Ln-lanthanoid; B = Ni, Co) compounds with the orthorhombic perovskite structure have been prepared by a solid state reaction. They are ferromagnets with relatively high Curie temperatures. The Curie temperature decreases with decreasing average radii of the Ln-ion. It is shown that the Ln(Co0.5Mn0.5)O-3 (Ln = Gd, Tb, Dy, Y, Ho) are metamagnets.