This document discusses a method to improve the performance of nonlocal means image denoising. It proposes a pre-processing step that eliminates dissimilar patches from the search neighborhood before denoising. A hard threshold is calculated based on the distribution of distances between noisy similar patches. The proposed Similarity Validation Based Nonlocal Means (NLM-SVB) method shows improved PSNR and SSIM over nonlocal means and other recent variations when retrieving a denoised image.