In this study, ferrous iron oxidation rates of a Leptospirillum ferriphilum dominated culture were determined over the temperature range of 2-50oC at pH below one. The results show that at pH 0.9 the culture oxidizes iron within the temperature range of 10°C to 45°C. Using the Arrhenius equation, an Ea value of 89.9 ± 6.75 kJ/mol was calculated. From the data fitted to Ratkowsky Equation, the optimum, minimum and maximum temperatures were 35 ± 1.5, 9.96 ± 1.72 and 42.93 ± 0.64 °C for this culture, respectively. The redox potential of the solution becomes more positive, which was the maximum (650-700 mV) at temperatures between 19-40 oC due to completing biological oxidation and increasing in ferric iron concentration.