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The present work examines experimentally the effect of different direct water injection strategies on NOx emissions and performance in a direct injection hydrogen fueled engine. Three water injection strategies were considered including; injection at the suction, compression and expansion strokes. Both injection timing as well as quantity were varied for each strategy. The water injection configuration relative to the spark plug has been also evaluated. The results showed that water injection during expansion stroke has a minor effect on NOx emissions, which has been already formed. Noticeable effect could be achieved when water is injected at the later stages of the compression stroke. Reduction of NOx emissions is strongly dependent on the injection timing as well as quantity of the injected water. Optimum injection timing, for maximum NOx reduction, advances with the increase of the quantity of water being injected.