The paper presents the thermal aspects of possibilities for using the Nano Encapsulated Phase Change Materials with the water as the base fluid as a cooling solution for high power light emitting diodes (LED). The approach used is based on the numerical modelling with control volume method as the theoretical background. The cooling device used in simulations is mini-channel heat sink with straight fluid flow channels. The results confirm the fact that Nano Encapsulated Phase Change Materials with the water as the base fluid, correlated with mini-channel heat sink, might be the suitable candidate for cooling of high power light emitting diodes (LED).