Lemon juice was treated with Penicillium occitanis pectinase at various enzyme concentrations (0–1200 U/L), temper-atures (25–50◦C) and times (0–90 min). The effect of these enzymatic treatments on the viscosity of the juice wasevaluated. The optimum treatment conditions were: enzyme concentration 600 U/L, time 45 min and temperature30◦C. Their application led to a 77% and 47% reduction of viscosity and turbidity, respectively. The enzymatic treat-ment was followed by ultrafiltration (cutoff value = 15 kDa). Analysis of the clarified juice indicated that enzymedepectinization permitted a higher permeate flux and a higher juice quality. The lemon juice obtained was clear, sta-ble and characterized by viscosity = 0.7 mPa s, turbidity = 0.17 NTU, clarity (A650nm) = 0.063 and color (A420nm) = 0.232.Microbiological study showed that lemon juice was free from aerobes, molds, enterobacteriaceae and coliformsand was microbiologically stable during 3 months storage. Results suggested that enzymatic treatment coupled toultrafiltration could be used for production of lemon juice with high commercial value.