We demonstrate the minority carrier lifetime measurements of polycrystalline silicon nanowires (poly-SiNW) films passivated with aluminum oxide (Al2O3) deposited by atomic layer deposition (ALD). The poly-SiNW films were prepared by metal-assisted chemical etching of poly-Si films. The poly-Si films were prepared by solid phase crystallization of a-Si films deposited by radio-frequency sputtering on aluminum induced crystallized poly-Si template. The deposition of an ALD-Al2O3 passivation layer and subsequent annealing enabled us to measure effective minority carrier lifetime of the poly-SiNW films. The effective lifetime was found to be 5.76 μs. This result indicates that ALDAl2O3 is beneficial to surface passivation of poly-SiNW films.