We investigate the differences in electrochemical anostructuring of CuInS2 and CuGaS2 crystals. It is shown that thermal reatment of CuInS2 crystals either in vacuum or in Zn vapors is a procedure providing necessary electrical conductivity to the as-grown high-resistivity crystals for a consequent electrochemical nanostructuring, while in CuGaS2 crystals treatment in Zn vapors at temperatures higher than 700 oC is needed to make them suitable for electrochemical nanostructuring. Porous CuInS2 structures with a uniform porosity and the pore diameter controlled by the crystal conductivity are demonstrated, while the porosity of CuGaS2 structures is inhomogeneous. Possibilities of luminescence enhancement via thin Au and Cu film deposition onto nanostructured CuGaS2 surfaces or ITO films onto CuInS2 surfaces are also investigated.