A zoom lens system comprising: a first lens unit having negative optical power; a second lens unit; and at least one subsequent lens unit, wherein in zooming, the first lens unit moves along an optical axis, and at least an interval between the second lens unit and a lens unit which is one of the at least one subsequent lens unit varies, in focusing, an interval between the first lens unit and the second lens unit varies, at least one aspheric surface is included in the at least one subsequent lens unit, and the condition: 0.1