Introduction: Chlorhexidine (CHX) and sodium fluoride (NaF) were reported as substances that could alter the tita- nium layer and would affect the corrosion resistance of CuNiTi. It was caused Nickel and other ions released and changed to its surface structure. Nickel is classified as a chemical carcinogen. This study was conducted to examine the NaF effect of corrosion of CuNiTi archwire in CHX mouthwashes (Nickel ion release and the surface structure analysis). Methods: 90 samples of CuNiTi archwires were divided into 3 groups according to its immersion solution. Group 1, artificial saliva (Saliva; control group); Group 2, Saliva and 0.1% chlorhexidine gluconate mouthwash (Saliva-CHX); Group 3, Saliva, 0.05% NaF, and 0.12% chlorhexidine gluconate mouthwash (Saliva-CHX NaF). The group further divided into 3 subgroups corresponding to the time of the archwire immersed, i.e., 2, 4, and 6 weeks. Samples analysed with atomic absorption spectrophotometer (AAS) and a scanning electron microscope (SEM). Re- sults: The highest amount of nickel ion release was in Saliva-CHX NaF group compared to Saliva-CHX group for each time observation. The data obtained were analysed statistically by using Kruskal Wallis test to compare the amount of nickel release in week 2, 4 and 6. Nickel ions released were significantly different between mouthwashes solutions in all groups (p-value<0.05). Conclusion: The CuNiTi orthodontic wire is further susceptible to corrosion when NaF is included to CHX mouthwashes. The amount of nickel ion release of the study was within the safe limit.