Development of environmental benign as well as low cost metal precursor based catalyst is a challengefor chemical industry. In this work we report Bi promoted SBA-15 catalyst for vapour phase Beckmannrearrangement reaction of cyclohexanone oxime. The three different Bi loaded SBA-15 catalysts are pre-pared and characterized by BET surface area and porosity measurement, small angle X-ray scattering,wide angle X-ray diffraction, field emission scanning electron microscope, high resolution transmis-sion electron microscope, ultraviolet–visible spectroscope, Fourier transform infrared spectroscopy andtemperature programmed desorption techniques. Further, catalytic activity is optimized by changingreaction temperature, pre-treatment temperature and pre-treatment time so that 100% cyclohexanoneoxime conversion and 100% ε-caprolactam selectivity has been achieved. Role of solvent, silylation andtime on stream has also been examined. The TPD profiles of all three bismuth loaded samples are mainlycharacterized by weak acidic sites or surface silanol groups. The FTIR profile shows hydroxyl rich surfacein the vicinity of bismuth at Bi-SBA-15 (Bi/Si = 1/100). Based on catalyst characterization and activity datacorrelation, it can be suggested that protonation at oxime oxygen can be triggered by surface silanol in thevicinity of a Lewis acid centre bismuth. The high space-time-yield of caprolactum was 114.3 mol g_cat⁻¹h⁻¹was obtained.