Methods of depositing fluorine-free tungsten by sequential CVD pulses, such as by alternately pulsing a fluorine-free tungsten precursor and hydrogen in cycles of temporally separated pulses, are provided. Some methods involve depositing fluorine-free tungsten by sequential CVD without depositing a tungsten nucleation layer. Methods also include depositing tungsten directly on a substrate surface using alternating pulses of a chlorine-containing tungsten precursor and hydrogen without treating the substrate surface. Methods also include depositing a tungsten layer using a reducing agent and fluorine-free tungsten-containing precursor and depositing bulk tungsten in sequential CVD cycles of alternating pulses of hydrogen and a tungsten-containing precursor.