The number of studies analyzing chemistry textbooks has steadily increased over the years and has notably surged in the past decade. In this literature review, we examine the research literature on chemistry textbooks. The review spans 40 years of research (from 1981 to 2021) and includes 79 studies published in over 20 different journals, analyzing secondary and postsecondary chemistry textbooks used in more than 17 countries. We synthesize the samples and methods used as well as the findings of the studies around chemistry textbooks. Based on this synthesis, we provide multiple concrete implications to improve the rigor of future studies of chemistry textbooks because most of the articles in our review lack a discussion of the limitations of their studies, half do not use any theoretical or analytical framework(s) to guide the design of their studies and the interpretation of findings, and a quarter do not specify the country of use for the textbooks in their samples. Additionally, we provide concrete recommendations for textbook developers to improve the quality of chemistry textbooks. Importantly, textbook developers need to ensure that their products are grounded in research and theory about student learning.