Using natural gas-acetylene mixed fuel system an atomic absorption spectrophotometric methoa is developed for the determination of trace metals in drinking waters. Optimum operating conditions are established in terms of fuel and air flow rates for the determination of sodium, potassium, zinc, nickel, cobalt, strontium and magnesium in drinking waters. Compared with the conventional acetylene-air method the proposed method provides an overall 25-40 percent increase in the absorption sensitivity with about 50 percent economy in acetylene consumpt ion. The concentra t ion data a re reported at 25 confidence level for replicate measurements, together with lower detection limit for each trace metal estimated.