This work investigates the fatigue resistance of reinforced Ultra High Performance Fiber Reinforced Cementitious composite (R-UHPFRC) beams with special consideration of steel rebar – UHPFRC interaction under tensile stresses due to bending. Experimental testing of full-scale beams reveals that the fatigue resistance depends on both minimum and maximum loadings in the cycle. The increase of stress range in the rebar during the fatigue process is discussed and quantified. Finally, recommendations for fatigue verification of R-UHPFRC beams are given.