Vegetable protein diets (VPDs) in patients with CKD may have positive biological actions and possibly clinical impact. This is an integrative review of studies comparing a vegetarian to a non-vegetarian diet in adults with CKD in nondialysis treatment. The evaluated outcome was the impact in renal function assessed by eGFR or creatinine clearance. MEDLINE (accessed by PubMed) was searched up to September 8, 2020. Two independent reviewers extracted the data and assessed the quality of the studies. From 341 articles retrieved, 4 studies were included for analysis, assessing 324 patients. One study showed that a ketoanalogue-supplemented vegetarian very low- protein diet had benefits in relation to a conventional low-protein diet while, the other three studies demonstrated no difference in kidney function between the evaluated diets. Additional studies are needed to assess the benefits of vegetarian diets for their potential inclusion in clinical recommendations for the management of CKD. [resumo fornecido pelo autor]