An optical fiber cable has a highly reduced diameter. The cable has a central strength member; a number of tubes containing loosely arranged optical fibers, each tube having a thickness, and each optical fiber having a coating; and a protective outer jacket, wherein the filling coefficient of optical fibers in at least one loose tube is .gtoreq.45.degree./0. The tubes are made of a material having an elasticity modulus .gtoreq.700 MPa; and the optical fibers are SM-R fibers having a microbending sensitivity .ltoreq.4.0 dBkm.sup.-1/gmm.sup.-1 at a temperature of about -30.degree. C. to +60.degree. C. at about 1550 nm.