Abstract Purpose: To evaluate and compare the shear bond strength (SBS) of metallic brackets bonded to enamel by Conventional Bonding System using six different light curing units. Materials and methods: Sixty human permanent maxillary premolars were embedded in acrylic resin using PVC rings as molds and assigned to 6 groups. Each teeth bonded with transbond XT adhesives and cured with the LED light curing unit of the respected group. Ten Samples Of Group – 1 was cured with BLUEPHASE N , Group – 2 with BLUEPHASE NM ,Group – 3 with3M ESPE EliparTMS10, Group – 4 with 3MESPE EliparTM Deepcure, Group – 5 with WOODPECKER B PLUS CURE and Group – 6 with WOODPECKER I LED were used and each sample was cured for about 3 sec. After bonding, the specimens were submitted to shear bond strength test using universal testing machine at a crosshead speed of 0.5 mm/min. Results: The highest mean SBS was obtained with the samples cured with 3MESPE EliparTM with a curing time of 3 sec(18.5 MPa). ANOVA test shows a statistically significant difference between the groups expect between group 1 and group 2 and between group 5 and group 6. Conclusion: Polymerization with all the six LED curing lights resulted in SBS values that were clinically acceptable for orthodontic treatment in all groups. Curing with 3MESPE EliparTM Deepcure gave a higher bond strength than other groups cured for a short time.