Pectate lyase (PEL) has been purified by hydrophobic, cation exchange and size exclusion column chromatographies from ripe banana fruit. The purified enzyme has specific activity of 680±50pkatmgprotein −1 . The molecular mass of the enzyme is 43kDa by SDS–PAGE. The pI of the enzyme is 8 with optimum activity at pH 8.5. Analysis of the reaction products by paper and anion exchange chromatographies reveal that the enzyme releases several oligomers of unsaturated galacturonane from polygalacturonate. The K m values of the enzyme for polygalacturonate and citrus pectin (7.2% methylation) are 0.40±0.04 and 0.77±0.08gl −1 , respectively. PEL is sensitive to inhibition by different phenolic compounds, thiols, reducing agents, iodoacetate and N-bromosuccinimide. The enzyme has a requirement for Ca 2+ ions. However, Mg 2+ and Mn 2+ can substitute equally well. Additive effect on the enzyme activity was observed when any two metal ions (out of Mg 2+ , Ca 2+ and Mn 2+ ) are present together. The banana PEL is a enzyme requiring Mg 2+ , in addition to Ca 2+ , for exhibiting maximum activity.