The application of modern electron microscopy and X-ray diffraction techniques to the study of ancient pigments has proved to be very useful. In the present work we report the study of pigments from Mexica (Aztec) culture which developed in Central Mexico from 1325-1521 AD; we study the blue, ochre, red and black pigments. We found in the most cases the paints were made of a clay substrate that contained metal particles such as Fe, Ti, Mn and Zn, in different phases. This technology was found similar to that of earlier mesoamerican cultures.