In recent years it became clear the relevance of photonic crystals when considering a nonlinear interaction. It has been shown in many occasions that the structuring of the material results in a clear enhancement of the nonlinear interaction. However, not too many structuring technologies can be applied successfully to materials that exhibit very good physical properties for the nonlinear generation of light. One of these is KTiOPO<sub>4</sub> (KTP), an inorganic material with high nonlinearity, large electrooptical coefficients, and very good transparency in the near infrared and visible range. In this paper, we propose a novel technique for growing two-dimensional KTP-air photonic crystals by liquid phase epitaxy employing a two-dimensional ordered macroporous Si matrix as a template.