The upflow anaerobic sludge blanket reactor (UASBR) is efficient in treating wastewater, especially when dissolved organic matter is present. In this study, a laboratory scale of an UASBR was configured to treat biscuit wastewater. Hydraulic retention time (HRT), organic loading and hydraulic loading parameters were used as design criteria and wastewater parameters such as pH, alkalinity, chemical oxygen demand (COD), suspended solids (SS), total volatile acid (TVA) and total solids (TS) were investigated as performance criteria. Substrate utilization rate in terms of COD, gas composition in terms of CH(4) and total volatile solids changing with depth in the reactor were also determined. The COD removal rate was attained to be 92%. Methane gas was about 60-65% of the biogas produced. Moreover, a mathematical model was studied and kinetic coefficients were obtained for this particular wastewater. Kinetic coefficient Y and endogenous decay coefficient k(d) were obtained as 0.036 kg TVS/kg COD-rem and 4.084 day(-1), respectively.