Titanium nitride thin films have been deposited using reactive direct current magnetron sputtering onto stainless steel substrates. The only deposition condition which has been varied is the ratio of argon to nitrogen in the sputtering gas. While the films deposited at low nitrogen partial pressures exhibited a strong (111) preferred orientation, with increasing fraction of nitrogen in the sputtering gas, the preferred orientation of the films changed from (111) to (002). The accompanying changes in the microstructure and growth morphologies of the phases in these thin films have been investigated by x-ray diffraction and transmission electron microscopy. In addition, the effect of orientation on the optical reflectance of the films has been investigated. (C) 2003 American Vacuum Society.