The main purpose of this work was to produce nanotubes using a two step method: mechanical alloying and heat treatment. Mechanical Alloying (MA) was used to prepare the monometallic Co3C carnide and the bimetallic C-25%at Ni-25%at Mo carbide with Ti impuririties by milling of pure elemental powders of cobalt, molibdenum, titanium and carbon, in a high-energy rotatory mill under an Ar atmosphere. The nanocrystalline carbides were used to produce metal filled nanotubes and nanoparticles, by means of precipitation after heating for 15 minutes at 800°C. Microstructural characterisation of the as-milled and heat-treated powders was performed using Transmisssion Electron Microscopy (TEM) techniques. It was possible to obtain filled nanotubes, carbide nanorods, and observe a nucleation phenomena inside carbon cavities.