<b>A General Review on Bioanalytical Method Development and Validation for LC MS MS</b> Rapid growth in the use of LC MS MS for the analysis of drugs in biological matrices has been compelled by the need for timely and high quality data at every stages in drug discovery and development process from throughput screening of drug candidates and rapid data generation for pre clinical studies to almost real time analysis of clinical samples. A well developed bioanalytical development and its validation plays a pivotal role in achieving the goals. . The aim behind this review is to enlighten the need of validation which provide a practical approach for determining the different parameters like selectivity, specifity, limit of detection, lower limit of quantitation, linearity, range, accuracy, precision, recovery, stability, ruggedness, and robustness to help the perfect studies of pharmacokinetic, toxic kinetic, bioavailability and bioequivalence. Bio analysis study is for the quantitative determination of drug and their metabolites in biological fluids. Accurate and robust methods for quantitative analysis of drug and their metabolites are important for the successful conduct of pre clinical, bio pharmaceutics and clinical pharmacology. LC MS MS bioanalysis , Bio analytical method development,Validation parameters, sample Preparation LLE, SPE 1340-1347 Issue-4 Volume-2 Ashutosh Badola | Preeti Joshi | Preeti Kothiyal