We established optimum washing and sanitizing conditions for fresh-cut lettuce using sodium hypochlorite to reduce microbial hazards. Reduction of microbial hazards, including total aerobic bacteria, Escherichoa coli, and Staphylococcus aureus at different sodium hypochlorite concentrations (0-500 ppm), immersion times (0-20 min), temperatures (0-30$^{circ}C$), and washing times (0-4 min) was evaluated. The optimum washing and sanitizing conditions using sodium hypochlorite for lettuce were determined as immersion at more than 50 ppm for 1 min at 20$^{circ}C$ and washing twice for 30 sec after dipping. Application of these optimum conditions will improve safety and added value of lettuce as a fresh-cut-food without detrimental effects on sensory characteristics.