The directional solidification of MgO–ZrO₂ eutectic has been investigated by the Bridgman type method. The melting was conducted using a Mo crucible in an argon atmosphere at the growth rate of 10–20 mm/h. Colony-free structures were obtained at these growth rates. The lamellar morphology as well as the fibrous morphology has been observed in the same sample. The orientation relationship was examined by electron diffraction and was determined as a cube/cube relation for the fibrous morphology. It was observed that the fiber rotated to the matrix within 5°. The orientation relationship for the lamellar morphology was given as (010)ZrO₂//(111)MgO and [100]ZrO₂//[110]MgO. The lamellar interface was almost (010)ZrO₂ which was parallel to (111)MgO.