INTRODUCTION: The majority of contemporary tooth whitening involves the use of either hydrogen peroxide or Carbamide peroxide as the bleaching agent. A recent increase in the treatment options of discoloured teeth has led to the development of various new techniques and materials. With recent development in bleaching techniques, many auxiliary apparatuses have been introduced for efficient bleaching. AIM: The purpose of the present study is to compare and evaluate the efficacy of In-office bleaching 37.5% hydrogen peroxide and At-home bleaching 15% Carbamide peroxide using different activation systems. MATERIALS & METHODS: Total of 80 freshly extracted human incisor teeth were selected, sectioned below CEJ and further stained using extra strong black tea and kept for 24 hours. The samples were thoroughly washed and cleaned of external stains and evaluated for pre-shade using spectrophotometer. Samples were divided into groups and bleached using different concentrations, methods and activation systems. Post shades were evaluated and the samples were subjected to statistical analysis. RESULT & CONCLUSION: Carbamide peroxide (15%) used in home bleaching is as effective as 37.5% hydrogen peroxide. On comparing in-office (37.5% hydrogen peroxide) with at-home (15% carbamide peroxide) it can be concluded that home bleaching with higher concentration of carbamide peroxide resulted in a better shade change. 37.5% hydrogen peroxide along with Laser activation resulted in superior immediate results but showed increased rebound of color after 1 week.