A taking lens system is provided with, from the side of the object to be photographed, a first lens unit (G1) having positive optical power, a second lens unit (G2) having negative optical power, a third lens unit (G3) having positive optical power and a fourth lens unit (G4) having positive optical power. Zooming is performed by moving the first to fourth lens units (G1) to (G4), and focusing is performed by moving the fourth lens unit (G4). When the distance from the most object-to-be-photographed side surface (r1) of the first lens unit (G1) to the imaging surface at the wide angle end is TLw, the overall focal length of the taking lens system at the telephoto end is ft, the overall focal length of the taking lens system at the wide angle end is fw, and the focal length of the first lens unit (G1) is fl, relationships 0.5.ltoreq.TLw/ft.ltoreq.1.0 and 6.0.ltoreq.fl/fw.ltoreq.20.0 are satisfied.