In this paper a novel method for 3D model content-based search and retrieval based on the 3D Radon Transform and a querying-by-3D-model approach, is presented. Descriptors are extracted using the 3D Radon Transform and applying a set of functionals on the transform coefficients. Similarity measures are then created for the extracted descriptors and introduced into a 3D model-matching algorithm. This results to a very fast and accurate matching method. Experiments were performed using two different databases and comparing the proposed method with others. Experimental results show that the proposed method can be used for 3D model search and retrieval in a highly efficient manner.