Purpose: This review critically compares the available clinical and laboratory methods for assessing the fit of an implant prosthesis. Materials and Methods: MEDLINE and PubMed databases were searched for studies related to the fit of implant prostheses or the effect of misfit. Different combinations of key words were used. The screening procedure was performed in two stages. In the first stage, the relevant articles were selected. In the second stage, from those articles, specific inclusion and exclusion criteria were applied. Results: Fifty-four articles were selected. Two different techniques were identified: in vitro and in vivo. The advantages, disadvantages, and limitations of each technique are discussed. There are clear limitations for the in vivo techniques. The in vitro techniques provide a more accurate measure of prosthesis misfit. Conclusions: Because of the variety of techniques and the different parameters assessed by each, it is useful to combine several techniques to assess the accuracy of fit, quantify the effect of misfit, and subsequently determine an acceptable level of fit. Schlagwörter: dimensional measurements, implant framework, modeling methods, passive fit, prosthesis fit