The optimum conditions for biological hydrogen production from food waste by Clostridium beijerinckii KCTC 1875 were investigated. The optimum initial pH and fermentation temperature were 7.0 and $40^{circ}C$, respectively. When the pH of fermentation was controlled to 5.5, a maximum amount of hydrogen could be obtained. Under these conditions, about 2,737 mL of hydrogen was produced from 50 g COD/L of food waste for 24 h, and the hydrogen content in the biogas was 38%. Hydrogen production rate and yield were about 108 mL/L$cdot$h and 128 mL/g $COD_{degraded}$, respectively. High concentrations of acetic (< 5,000 mg/L) or butyric acid (< 3,000 mg/L) significantly inhibited hydrogen production.