Methylcobalamin, a vital vitamin B12 analog, is susceptible to degradation under thermal stress, leading to changes in PH. Trigeminal neuralgia, diabetic neuropathy, facial paralysis and megaloblastic anemia can be treated by the use of Methylcobalamin injection. A new simple, precise, economically viable and efficient High-Performance Liquid Chromatographic (HPLC) method for the estimation of Methylcobalamin (MeB12) in bulk drugs and pharmaceutical dosage formulations was developed and validated. The method was validated for linearity, accuracy, precision, LOD, LOQ and robustness as per ICH guidelines. The method was tested with commercially available MeB12 drugs and the concentration methylcobalamine was found to be accurate.