Results on the deposition of aluminum nitride thin films on silicon (111) substrates by pulsed laser deposition are reported. A KrF excimer laser was used to ablate in vacuum an AlN target. The intensity and the repetition rate of the laser as well as the substrate temperature were varied and their effects on film properties were determined. The AlN films were characterized by several techniques such as in situ laser interferometry, X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscopy and transmission electron microscopy. At a deposition temperature of 500 °C and a laser intensity of 1 × 108 W/cm2, highly oriented AlN layers are deposited. Increasing the laser intensity leads to the presence of metallic Al in the films. As temperature is increased from 500 to 920 °C, the growth rate is found to decrease but the crystalline structure as well as the smoothness of the films are both significantly improved. It is also found that a reduction of the growth rate by varying the repetition rate from 30 to 10 Hz leads to a further improvement of the crystalline quality of the AlN layers.