Aim: Most metallic orthodontic attachments contain nickel. As a result, various amounts of this known allergen can leach into the patient’s body. The existing methods to test the amount leached in vitro do not apply to all orthodontic attachments and require sophisticated and expensive material technical. Instead, a simple, do-it-yourself test is proposed. Method: The appliances presumed to endanger the health of the patient are immersed, along with known samples (controls), in a solution recommended by ISO for the accelerated corrosion of stainless steel alloys for dental castings. To allow detection, the solution is added with reagents specific for nickel or iron and then gelled. Results: After a few hours, the degree of attack and the nickel and iron releases can be inferred from the size of the colored spots generated around the immersed attachments. Conclusion: The method has been successfully applied to wires, brackets, and expansion screws, detecting the attachments that have a greater likelihood of harming the patient. World J Orthod 2003;4:348–357.