The objective of this study is to investigate dark anaerobic fermentation as a suitable technology for producing hydrogen. Tests were run at two different initial sucrose concentrations (50 and 100g/l) in a pilot scale reactor under batch conditions. The digester consists of a vessel connected to a gas collection system and equipped with a stirrer (max. speed 30rpm) and a pH and temperature control system. Gas produced could be monitored thanks to a gas counter, while the composition could be analyzed through a gas-cromatograph. Temperature, pH and ORP could also be registered via PLC. Anaerobic digested sludge, pre-treated for 24h at pH=3 to inhibit methanogenic bacteria, was used as inoculum, and then fed with a medium containing the sucrose solution, salts and micronutrients. Chemical and biological analysis were performed at different times on samples for the determination of sucrose and biomass concentration, ATP and VFA_s. No pH and temperature regulation occurred during fermentation, so pH decreased constantly, while temperature remained at 20°C. In terms of gas produced, the best results were observed at 100g/l of sucrose with 23l of hydrogen produced against 4l at 50g/l. In fact sucrose was mainly consumed at 100g/l with a conversion of 44%, instead of 25%. However for both experiments yield remained at 0.20÷0.32 mol H₂/mol sucrose, because of low temperatures and development of a mixed culture. A kinetic approach was proposed for future experiments under continuous conditions, suggesting that inlet sucrose concentration should vary in a range of 60÷70g/l for maximizing hydrogen production.