Heavy metal contents in dicyclomincHCl, ethambutol, pyrazinamide and furazolidone drugs were determined by inductively coupled plasma (ICP) - mass spectrometry (MS). The drugs Were analyzed for Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg, Pb metals by selecting a suitable isotope. Cr, Fe, Ti and Cu were observed to be highest in dicyclomincHCl, ethambutol, pyrazinamide and furazolidone respectively. Ni and Ha were absent in all the four drugs, while traces of Cd were present in ethambutol and pyrazinamide. Analytical results showed that ICP-MS method is useful for monitoring inorganic impurities present in such drugs.