The corning (R) Advanced Flow (TM) Reactor (AFR) was used for continuous synthesis of biodiesel from fresh oil and used cooking oil. All Experiments were carried out in AFR at different parameters such as feed flow rates, temperature and concentration of catalyst to study the optimum operating conditions for synthesis of biodiesel. Two different oils (fresh oil (FO) and used cooking Oil (CO)) were used for continuous flow synthesis of biodiesel. The maximum oil conversion of 99 and 93% were achieved in presence of 2 wt.% of catalyst (sulfuric acid) at 80 degrees C and feed flow rate of 30 mL/h in AFR (TM) for FO and CO respectively. The composition of fatty acid methyl esters (FAMEs) in finished biodiesel product was found to be 0.2788 mol/L and 0.2742 mol/L for FO and CO respectively. A mathematical model was developed, assuming that the AFR (TM) module behave as a PFR. The model consists of ordinary differential equations, which were solved by Ruler's method in MATLAB to study the change of concentration of oils against time at different parameters. The simulation results shown good agreement with the experimental results.