An objective lens system for endoscopes comprising, in order from the object side, a first lens component having negative refractive power, a second lens component having positive refractive power and a third lens component having positive refractive power; wherein astigmatism is corrected favorably by using an aspherical surface in the third lens component or an aperture stop is arranged between the second lens component and an image surface of the objective lens system, and aberrations including chromatic aberration are corrected favorably.