Objective The aim of this clinical study was to determine the efficacy of Uncaria tomentosa (cat's claw) against denture stomatitis (DS). Study Design Fifty patients with DS were randomly assigned into 3 groups to receive 2% miconazole, placebo, or 2% U tomentosa gel. DS level was recorded immediately, after 1 week of treatment, and 1 week after treatment. The clinical effectiveness of each treatment was measured using Newton's criteria. Mycologic samples from palatal mucosa and prosthesis were obtained to determinate colony forming units per milliliter (CFU/mL) and fungal identification at each evaluation period. Results Candida species were identified with HiCrome Candida and API 20C AUX biochemical test. DS severity decreased in all groups (P <.05). A significant reduction in number of CFU/mL after 1 week (P <.05) was observed for all groups and remained after 14 days (P >.05). C albicans was the most prevalent microorganism before treatment, followed by C tropicalis, C glabrata, and C krusei, regardless of the group and time evaluated. U tomentosa gel had the same effect as 2% miconazole gel. Conclusions U tomentosa gel is an effective topical adjuvant treatment for denture stomatitis. © 2014 Elsevier Inc. All rights reserved.