A simple, compact, double-pass pumped Nd:YVO₄ thin disk laser is demonstrated. Its continuous-wave performance with different Nd doping concentrations and thicknesses is investigated experimentally. The maximum output power of 17.7 W is achieved by employing a 0.5 at.% doped sample, corresponding to an optical-to-optical efficiency of 46% with respect to the absorbed pump power. In addition, a numerical analysis and an experimental study of the temperature distribution, and thermal lens effect of the Nd:YVO₄ thin disk, are presented considering the influence of the energy transfer upconversion effect and the temperature dependence of the thermal conductivity tensor. The simulated results are in good agreement with the experimental results.