Simple and sensitive infrared  spectrophotometric method have been developed for the estimation of  isoniazid in tablet dosage form and the Beer’s concentration range was found to be 0.5mg-2.0 mg. The correlation coefficient for the method was found to be 0.9 and the developed method was analyzed for specificity, linearity of response, precision and accuracy; thus the proposed method could be adopted for routine analysis of bulk drug and its formulation.