We have used scanning tunneling microscopy (STM) to investigate the fractal character of gold deposits grown by electroreduction of hydrous oxide layers. We have been able to precisely measure the fractal dimension (D’) of several samples grown under different conditions by processing three‐dimensional STM images. Lake patterns were generated by computer simulating the filling with ‘‘water’’ up to a given level of the surface topography. Lake perimeter (L) versus area (A) relationships could be established leading to a fractal description (L∝AD’/2) of the sample surface.