An optical fiber cable fixing structure capable of properly meeting any optical fiber cable having a wide range of diameters without deteriorating optical transmission characteristics when the optical fiber cable is fixed to a fixed-member. The optical fiber cable fixing structure includes an arcuate inner peripheral surface which is to be contacted with a side surface of the optical fiber cable, a first cable holding member secured to the fixed-member, an arcuate inner peripheral surface which is to be contacted with a side surface of the optical fiber cable, a second cable holding member slidably mounted on the fixed-member for sliding toward and away from the first cable holding member, and a stopper for removably securing the second cable holding member at any desired position. A plurality of protuberances each having a sharp tip are provided on the inner peripheral surfaces of the first and second cable holding members, respectively.