An oil sump (2) for an internal combustion engine, having at least a monolithic concave member (5) defining a vessel (6) for containing lubricating oil and defined at the top by a peripheral edge (7) securable to a block (4) of the engine; and an oil intake pipe (3) integral in one piece with the sump; wherein the oil intake pipe (3) projects inside the vessel by opposite ends, a first (11) located at a bottom wall (13) of the concave member (5), and a second (12) substantially flush with the peripheral edge (7); the oil intake pipe (3) being formed as a separate member from the concave member (5), and being fixed integrally to the concave member by the first end (11), at a given distance from the bottom wall, and by an intermediate portion (15); and the second end (12) of the oil intake pipe having a fast-fit fitting projecting beyond the peripheral edge.