The present invention relates to an oil separating device for crankcase ventilation of an internal combustion engine, comprising an oil separator having a gas inlet line, which has an outlet end, and a gap-defining element, wherein the gas inlet line for flowing blow-by gas has an inner wall and an outer wall, wherein an inner annular gap is formed or can be formed between the gap-defining element and the outlet end on the inner wall of the gas inlet line and an outer annular gap is formed or can be formed between the gap-defining element and the outlet end of the outer wall of the gas inlet line, wherein, in the flow direction, an inner baffle is arranged behind the inner annular gap and an outer baffle is arranged behind the outer annular gap.