A growing body of empirical evidence has consistently demonstrated that much publically and privately funded research is reported in a way that makes it difficult for the findings to be included in evidence syntheses or used by researchers, clinicians, policy makers, and the public. Poorly reported studies thus represent a significant waste of scarce resources. Reporting guidelines are one strategy that has been increasingly used as a method to improve the completeness or usability of primary and secondary research across a broad range of disciplines including psychology. We present a synopsis of two studies investigating the impact of the Transparent Reporting of Evaluation with Nonrandomised Designs statement and factors that affect authors' and journal editors' use of it and other reporting guidelines. We also make recommendations for future guideline development or revisions based on our experiences, provide details of resources for psychologists, and make suggestions for future research and recommendations for improving the transparency of reporting of psychological research.