A simple, sensitive, selective rapid spectrophotometric method has been developed for the determination of dasatinib in pure form and pharmaceutical formulations based on the ionissotiation reaction with BPB reagent, at PH_3.9 which is extractable at 420 nm. Beer’s law is obeyed in the concentration ranges 5-30 µg ml-1 and 3-18µg ml-1 for blood sample the developed method was applied directly and easily for the analysis of the Pharmaceutical formulations and blood sample. R.S.D was found to be 0.32679%, 0.54644% and Recovery 99.86% 99.9% respectively. The method was completely validated and proven to be rugged. The interferences of the other ingredients and excipients were not observed. The repeatability and the performance of the proved method were established by point and internal hypothesis and through recovery studies.