Objective center dot To investigate the effect of Wandai decoction combined with traditional Chinese medicine fumigation and washing in patients with chronic vaginitis after sintilimab treatment for small cell lung cancer. Methods center dot We recruited 80 patients who developed chronic vaginitis after sintilimab treatment for small cell lung cancer from Hainan General Hospital from January 2020 to June 2022; using a random number table, 40 were assigned to a control group and 40 were assigned to an observation group. The control group was treated with Wandai decoction, and the observation group was treated with Wandai decoction combined with traditional Chinese medicine fumigation and washing. The 2 groups were compared for improvement of the symptoms of vulvar pruritus subsidence time, leukorrhea recovery time, and traditional Chinese medicine symptom score; levels of the vaginal microecological environment factors immunoglobulin G, secretory immunoglobulin A, and pH; levels of the serum inflammatory factors C-reactive protein, tumor necrosis factor, and interleukin-6; and clinical efficacy. Results center dot After treatment, the observation group had significantly higher vulvar pruritus subsidence time, leukorrhea recovery time, traditional Chinese medicine symptom score, and pH value; significantly lower levels of C-reactive protein, tumor necrosis factor, and interleukin- 6; and significantly higher levels of immunoglobulin G, secretory immunoglobulin A, and total effective rate compared with the control group (all P < .0.001). Conclusions center dot Wandai decoction combined with traditional Chinese medicine fumigation and washing was effective in treating chronic vaginitis after sintilimab treatment for small cell lung cancer. The treatment ameliorated symptoms of leukorrhea abnormalities, vulvar pruritus, and local inflammation, and promoted the recovery of the vaginal microbial environment. Despite the limitations of our study (small sample size and lack of comparison between different types of chronic vaginitis, which hinders the confirmation of extensive efficacy), we consider Wandai decoction combined with traditional Chinese medicine fumigation and washing worthy of promotion and application in clinical practice.