The effect of operation parameters, bias and nitrogen partial pressure in the microstructure and properties of titanium nitride (TiN) films was investigated. The films were grown using hollow cathode discharge ion plating (HCD-IP) on stainless steel. The structure was studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Cross-sectional TEM (XTEM) was used to study the effect of bias, nitrogen partial pressure and pre-deposited Ti-interlayer on the microstructure of TiN films. Plane-view TEM was also employed to measure the grain size of the films. The values of hardness of the films were measured using an ultramicrohardness tester. The results showed that the hardness of the films ranged from 1686-3120 kgf/mm(2). The increase in bias enhanced (111) preferred orientation and columnar structure in TiN films. introducing insufficient nitrogen pressure lowered the crystallinity of the films. The presence of a (0001) preferred orientation in the pre-deposited Ti interlayer enhanced (Ill)preferred orientation in TiN films. This may be due to the similar atomic packing between (111) in TiN and (0001) in Ti. High hardness of TiN films was found to be associated with a large amount of Ti2N and smaller grain size. The order of the factors, which influence the hardness of the TiN film, is the presence of Ti2N, grain size of TiN, and (111) preferred orientation.