Microbial lipases are important enzymes in food and pharmaceutical industries. In this work, a Candida viswanathii lipase was purified by hydrophobic interaction chromatography on octyl Sepharose. The purification presented 78.4% yield and the enzyme was 8.7-fold purified, with specific activity 700.4 U/mg protein and 69 kDa molecular weight. Immobilization of the enzyme on the same support presented 72.5% yield and a derivative with 101% expressed activity (109.2 U/g support), indicating hyperactivation of the enzyme. Optimal activity for both free and immobilized lipase was observed at pH 4.0 and 45 degrees C. The free and immobilized lipase showed broad-range stability from acid to neutral pH, and apparent activation and stability on organic solvents. The derivative was 60-fold thermostabilized in relation to the free enzyme and fully retained its activity after four cycles of p-nitrophenyl palmitate hydrolysis. Slight activation was observed with dithiothreitol and beta-mercaptoethanol. The free and immobilized lipase efficiently hydrolyzed monoesters, simple and mixed long chain triacylglycerols, as well as soy lecithin. The activity and stability in acid pH, the organic solvent tolerance and the lecithin hydrolysis indicate high potential application of the enzyme and its derivative in textile, food and pharma industries and for chemical synthesis.