A method is provided for producing a ventilation bore in a thrust bearing of a crankcase of a reciprocating internal combustion engine by milling. The milling cutter is an angled-head milling cutter, which is introduced into the crankcase in the direction of a cylinder longitudinal axis and is moved in the direction of a crankcase longitudinal axis until the thrust bearing is perforated. Subsequently, the angled-head milling cutter is moved back in the direction of the crankcase longitudinal axis and removed from the crankcase by moving the angled-head milling cutter in the direction of the cylinder longitudinal axis. Internal stresses in the crankcase are avoided by the production of the ventilation bore, as a result of which the strength of the crankcase is increased.