Eye tracking has taken hold in second language acquisition (SLA) and bilingualism as a valuable technique for researching cognitive processes, yet a comprehensive picture of reporting practices is still lacking. Our systematic review addressed this gap. We synthesized 145 empirical eye-tracking studies, coding for 58 reporting features and applying a gap analysis to the codings. Although certain aspects of reporting, such as descriptions of auxiliary assumptions, equipment, and setup, were consistently implemented, we found significant variation and sometimes complete omission of crucial details surrounding aspects of data quality and of data preprocessing and cleaning. This lack of information hinders the evaluation of methodological rigor and overall study quality of eye-tracking research. We propose a set of field-specific reporting guidelines in the form of a checklist to improve the quality of data collected and contribute to the larger goal of advancing the replication and reproducibility of eye-tracking research in SLA and bilingualism.