The optimum conditions for determination of hafnium in zirconium matrix by FAAS were established (1% HF, 0,1% Al, max. 1% ZrOCl2). The effect of various inorganic acids (HF, HCl, HClO4, HNO3, H2SO4), as well as influence of comparable amounts of Fe, Ca and Mg on the Hf signal was also studied. ICP-AES was used as comparative method.