Intraoral scanners (IOSs) are used for capturing the direct optical impressions in dentistry. The development of three-dimensional technology and the trend of increasing the use of IOSs in dental office routine lead to the need to assess the accuracy of intraoral digital impressions. The aim of this review was to assess the accuracy of the different IOS and the effect of different variables on the accuracy outcome. An electronic search using PubMed with specific keywords to obtain potential references for review. A search of MEDLINE (PubMed) identified 507 articles. After title and abstract screening, 412 articles were excluded for not meeting the inclusion criteria and discarding duplicate references. Ninety-five articles were followed for full screening; only 24 articles were included in the final analysis. The studies indicated a variable outcome of the different IOS systems. While the accuracy of IOS systems appears to be promising and comparable to conventional methods, they are still vulnerable to inaccuracies.