Nanocomposite tungsten-aluminum oxide (W:Al 2 O 3 ) thin films were prepared by atomic layer deposition (ALD) using tungsten hexafluoride (WF 6 ) and disilane (Si 2 H 6 ) for the W ALD and trimethyl aluminum (TMA) and H 2 O for the Al 2 O 3 ALD. Quartz crystal microbalance (QCM) measurements performed using various W cycle percentages revealed that the W ALD inhibits the Al 2 O 3 ALD and vice versa. Despite this inhibition, the relationship between W content and W cycle percentage was close to that predicted by theoretical calculations based on the growth per cycle values of binary compounds. Depth profiling XPS showed that the (W:Al 2 O 3 ) films were uniform in composition and contained Al, O, and metallic W as expected, but also included significant F and C. Cross-sectional TEM revealed the composite film structure to be metallic nanoparticles ($1 nm) embedded in an amorphous matrix. The resistivity of these composite films could be tuned in the range of 10 12 -10 8 V cm by adjusting the W cycle percentage between 10% and 30%W. These films have applications in electron multipliers as well as electron and ion optics.