Electrically tunable laser action has been demonstrated in a dye-doped nematic liquid crystal (NLC) waveguide by holographic excitation. The optical feedback were provided by a transient grating induced by two-beam interference using Lloyd mirror configuration, and the distributed feedback (DFB) laser action was observed. Electrical tuning of lasing wavelength was realized due to the change of the effective refractive index of the NLC core layer caused by the reorientation of NLC molecules. The total shift of lasing wavelength was about 30 nm, which could be realized with less than about 1.4 V of applied voltage. Based on a waveguiding mode theory, numerical analysis of TM-guided mode in the presence of applied electric field was performed, and field-induced tuning of the lasing wavelength was investigated in detail. Prospects for the realization of a single-mode operation and tuning of the lasing wavelength was also shown. Based on the numerical results, single-mode operation of lasing was experimentally realized utilizing NLC with low refractive indices.