Background: Hyaluronic acid is widely used in the medical field. However, there is a lack of research about its effect on patients with certain risks, such as compromised wound healing commonly found in patients with poorly controlled type 2 diabetes. The aim of this study is to investigate the efficacy of hyaluronic acid on the post-extraction wound healing and pain in patients with poorly controlled type 2 diabetes. Material and Methods: The randomized controlled split-mouth study was designed, which included 30 patients with poorly controlled type 2 diabetes with a bilaterally same teeth in the lower jaw for extraction. The sockets treated with 0.8% hyaluronic acid represented the study group, while the sockets where hyaluronic acid was not applied represented the control group. Wound closure rate (WCR), clinical scores in wound healing scale (WHS) and pain intensity in Visual analogue scale (VAS) were recorded. Patients were followed up on 5 th , 10 th , 15 th , 20 th , 25 th day after tooth extraction.