Abstract: In an illuminating device for vehicles in which a light conductor made of light transmissive material having a predetermined light refractive index is placed between an outgoing light end of an optical cable and an incident light end of a lens body. The light conductor is shaped so as to cover the whole surface of the outgoing light end of the optical cable practically as well as to have an outgoing light surface shaped suitable for defining an illumination pattern. The lens body has the incident light end shaped to cover satisfactorily the outgoing light surface of the light conductor. Thus, the luminous flux from the outgoing light surface is emitted forward based on its shape as luminous flux of the desired light distribution without the waste of the luminous flux.