A sensitive, simple bio-analytical method using the Liquid Chromatography-Mass Spectroscopy (LC-MS) technique for the quantification of Lasmiditan (LST) in human plasma was developed and validated. The drug was extracted by using simple liquid-liquid extraction using a mixture of ethanol and diethyl ether in the ratio of 80:20 (v/v) for the sample preparation involved prior to LC-MS analysis. Separation of analytes and eletriptan (ETN) internal standard were chromatographed on a Phenomenex Luna C18 (100×4.6mm, 5μ) column. The mobile phase Methanol, Acetonitrile, and 0.8% Triethylamine (TEA) mixture in the ratio of 55:30:15 (v/v) with pH 5.6 was eluted using a gradient elution mode a with a flow rate of 0.6 mL/min.