The present invention provides a battery module case for an electric vehicle, wherein an electric vehicle battery provided to be utilized in an electric vehicle is accommodated inside the battery module case to improve assemblability. The battery module case for an electric vehicle is characterized by comprising: a case part which is formed by extrusion-molding an aluminum material, has a cavity formed in an inner profile corresponding to the outer profile of the battery for an electric vehicle, and is open in at least one end in the longitudinal direction, wherein a press-fit protrusion is formed along the edge of the open end; and at least one cover part which is formed by die-casting an aluminum material and provided so as to be coupled to the open end of the case part, and in which an extension portion is integrally formed to extend and protrude toward the case part from the edge thereof, at a position corresponding to the press-fit protrusion, so as to be press-fit on the edge of the press-fit protrusion, and both-side contacting grooves surrounding and closely contacting both sides of the press-fit protrusion are recessed in an end section of the extension portion.