Purpose: To evaluate the use of oxalic acid in restorations of noncarious cervical lesions. Materials and Methods: Twenty volunteers of both sexes between 24 and 55 years old, with at least two lesions that were restored with the techniques to be evaluated, were selected. Ninety teeth were randomly divided into two groups: group 1, two-step etch-and-rinse adhesive technique (control) and group 2, pretreatment with oxalic acid followed by the application of a two-step etch-and-rinse adhesive system. The adhesive system used was XP Bond (Dentsply) and the restorative composite resin was Durafill (Heraeus Kulzer). A modified USPHS method was employed for the clinical evaluation, taking into account the following criteria: retention (R), marginal integrity (MI), marginal discoloration (MD), postoperative sensitivity (S), caries (C), and anatomic form (AF). Clinical assessments were conducted by two examiners at baseline and after 6 months, 1 and 2 years. Results: After two years, the results of clinically satisfactory restorations (Alpha and Bravo) obtained for the control and experimental groups were: R (90.9%/93.33%), MI (100%/100%), MD (100%/100%), S (100%/100%), C (100%/100%), AF (100%/100%). Conclusion: Over a 2-year period, the use of oxalic acid as an agent of dentin pretreatment did not influence the clinical performance of restorations in noncarious cervical lesions. Keywords: adhesive, clinical trial, dentin hypersensitivity, oxalates