Standardized validated evaluation instruments are mandatory to increase the level of evidence in scar management. Scar assessment scales are potentially suitable for this purpose, but the most appropriate scale still needs to be determined. This review will elaborate on several clinically relevant scar features and critically discuss the currently available scar scales in terms of basic clinimetric requirements. Many current scales can produce reliable measurements but seem to require multiple observers to obtain these results reliably, which limits their feasibility in clinical practice. The validation process of scar scales is hindered by the lack of a “gold standard” in subjective scar assessment or other reliable objective instruments which are necessary for a good comparison. The authors conclude that there are scar scales available that can reliably measure scar quality. However, further research may lead to improvement of their clinimetric properties and enhance the level of evidence in scar research worldwide.