Procalcitonin is an acute phase reactant protein and a sensitive marker of severe bacterial infection. It is used to discriminate between infectious and non-infectious causes of inflammation and also is a marker of severe sepsis in the intensive care unit; however, diagnostic and prognostic value in pulmonary tuberculosis is still not well understood. This research was done to investigate the diagnostic & prognostic value of procalcitonin and alterations in serum calcium, phosphorus, C-reactive protein in TB patients at diagnosis, at the end of two months of intensive treatment and at the end of six months.