This study provides a critical review of the instruments developed for measuring service quality in restaurants. However, this study reviews the researches to examine the relationships between service quality, customer satisfaction (CS), and customer loyalty (CL) in restaurants. It is revealed that there are many attempts to develop instruments that aim to measure service quality in restaurants. SERVQUAL instrument, which measures service quality (SQ), has been used in many studies related to the tourism industry. However, the SERVQUAL is directly used as the basis of the SERVPERF and DINESERV instruments. Besides, since the GRSERV and CFFRSERV scales are based on DINESERV, the SERVQUAL plays an important role in the development of such scales. In addition to the instruments developed by modifying SERVQUAL, there are attempts to create different ones. In researches that develop a new SQ scale, the reasons underlying this need are stated as follows: 1) Some service quality components specific to restaurants and tourism sector not included in the current scales 2) Measuring the expectations and performance at the same time is not necessary 3) Current scales are insufficient for the unique types of restaurants, such as Fast Food, Upscale and Green Restaurants. CS and CL are the most common variables in the studies examining the SQ in restaurants. There is a divergence in the literature about whether service quality leads to satisfaction or satisfaction brings service quality. However, it can be said that there is a consensus that these two structures are in a very close relationship with each other. Another consensus in the literature is that CS and SQ are regarded as the determinants of CL. On the other hand, a considerable amount of research has been devoted to service quality, customer satisfaction, and customer loyalty, and it will be the case for future studies. However, the changes in business environments reveal the necessity of modification in the instruments that will pave the way to measure these concepts. A pandemic has recently affected the lives of businesses, and people and this new situation may require the addition of a new dimension to service quality instruments, like outbreak measures.