An electrically tunable pico projector adapting a liquid crystal (LC) lens as an active optical element is demonstrated. The electrically tunable focusing properties of the pico-projectors with different aperture sizes of the LC lenses are also investigated. The tunable ranges of the electrically tunable pico projectors are 350cm to 14cm. The response times are 1.2sec for the LC lens of 2mm aperture and around 5sec for the LC lens of 4mm aperture. The image performance of the electrically tunable focusing pico projector is demonstrated.