Background: Orthodontic treatment may have deleterious effects on the teeth structures. So, patients are advised for regular usage of prophylactic mouthwashes in order to prevent dental caries or periodontal diseases. Aim: The aim of this study was to assess and correlate the effects of acidulated phosphate fluoride on the load deflection of conventional, gold-plated nickel titanium and stainless steel arch wires. Materials and methods: Total 80 pieces of 0.016 inches round arch wires were received from IOS Company, USA, 40 sections from each type of arch wires. These pieces were divided into 8 groups with 10 cut pieces for each group, half of the groups were examined in wet conditions after being immersed with acidulated phosphate fluoride at temperature about 37°C for approximately 60 minutes, and the other half were tested in dry conditions. By using the Instron universal testing machine, a 3-point bending test was achieved, each specimen were loaded and examined with 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm of deflection. ANOVA and post-hoc Tukey’s test were used for the data analysis. Results: The loading forces of the conventional nickel titanium and stainless steel archwires were significantly reduced after immersion in acidulated phosphate fluoride. Gold-plated nickel titanium and stainless steel archwires have been distinguished of not being long-lasting and, as a result, have a trend to deteriorate or rub off leaving the nickel titanium or stainless steel core exposed. Conclusion: Conventional nickel-titanium and stainless steel archwires can be damaged with the use of acidulated phosphate fluoride; while the gold layer was rubbed off from the gold-plated archwires. Hence, the patient and the dentist should carefully use the fluoride-containing products.