A process for producing medical instruments (7) comprising the operations of extruding plastic material in order to obtain a heated tubular element (1) made of molten state plastic material, performing on the tubular element (1) a blow molding in order to obtain a plurality of medical containers (6). The process comprises the operation of calibrating the inner surface (6a) of the various medical containers (6), performed after the operation of extruding plastic material, in order to make smooth and continuous the inner surface (6a) of each of the medical containers (6).
