ABSTRACT: Pseudomonas aeruginosa NS2001 can produce high amounts of extracellular lipase in 5-liter fermenters. Using a culture medium comprised of (NH4)2SO4 0.13% (w/v), KH2PO4 0.09% (w/v), K2HPO4 0.06% (w/v), MgSO4.7H2O 0.02% (w/v), yeast extract 0.01% (w/v) and fructose 2% (w/v) in total volume of 4.0 liter, the optimal conditions were: inoculum size at 0.5% (v/v) of the culture volume, aeration at 1.0 vvm, agitation speed of 250 rpm, temperature at 37°C and control pH at 7.0. Under the conditions, this strain produced the highest amount of lipase at 1475.25 unit/mg protein at 48 hours.