Objective: To evaluate the shear bond strength of metallic brackets using the self-etching system after its activation and storage for 2, 5 and 9 day periods. Methods: A total of 64 bovine teeth were divided in four groups and prepared to receive the brackets. Initially (T1), 7 self-etching primer blisters were activated and used to bond the brackets of group I. The blisters were stored at a constant temperature of 4ºC for 2 (T2), 5 (T3) and 9 (T4) days and used to bond the brackets of groups II, III and IV, respectively. Results: No statistic difference was found in shear bond strength comparing groups I, II and III. However, a significant difference was found in group IV. Conclusion: The shear bond strength seems not to be affected by activation and storage of the self-etching primer at a mean temperature of 4°C for a 5 day period. More studies are necessary to evaluate other characteristics of the material after its activation and storage for long periods of time. AbstractKeywords: Shear bond strength. Self-etching system. Bovine enamel. Bond.