The optical design of a compact 2  ×   zoom lens in a lens barrel for miniature cameras is reported. The magnification in the optical system is achieved by means of changing positions of lens elements inside the lens barrel. Six lens elements are employed in the optical system, where up to four elements are actuated. Maximum travel distances for the moving parts are determined as 1.67 mm to reach a magnification of 2.06  ×  , and the total track length for the telephoto zoom lens state is 9.16 mm at its most extended configuration. Manufacturability of the proposed system is also discussed using a tolerance analysis. The designed optical system is suitable for use with image sensors up to 13 MP, and it can be employed in an endoscopic camera, where the optical zoom and compact design are beneficial. It is also suitable for smartphone cameras with further enhancements and integration of voice-coil-motors and/or MEMS actuators.