The objective of this study is to estimate the fatigue durability of a light-weight RC slab strengthened with PVA short-fiber. In this paper, a fatigue durability of this strengthened light-weight RC slab was tested under a wheel loading test. Influences of PVA short-fiber and light-weight aggregates on the punching shear strength were discussed. As a result, it was suggested to be able to evaluate the punching shear strength of RC slabs in consideration of these influences. A fatigue life of this strengthened light-weight RC slab was roughly consistent with the S-N curve that was calculated using this proposed method of the punching shear strength.