Method for manufacturing a crankcase of a piston compressor, wherein the piston compressor is provided with a crankcase which is provided with recesses for therein receiving cylinders and with at least an inlet opening, wherein from a flat sheet at least one substantially rectangular body blank is manufactured provided with the desired cylinder receiving recesses, wherein the body blank is then angle bent in an angle bending machine for forming a body part having a limited number of folds, wherein at least two substantially flat end walls are manufactured from a flat sheet, wherein thereupon the at least one body part and the at least two end walls are positioned with respect to each other using a positioning tool and are connected with each other with a welding robot for forming the crankcase. Also disclosed is a crankcase obtained with the method, and a piston compressor provided with such a crankcase.