A multisegmented Nd:YVO4 laser operating at 1342 nm that is in-band pumped by a wavelength-locked 878.6 nm laser diode is reported here. We achieve an output power of 12.45 W at 1342 nm for an absorbed pump power of 35.6 W, corresponding to an optical-to-optical efficiency of 34.9% and a slope efficiency of 36.1%. To the best of our knowledge, it is the highest optical-to-optical efficiency of Nd:YVO4 lasers operating at 1342 nm with an output power more than 10 W.