Myracrodruon urundeuva (aroeira-do-sertão) belongs to Anacardiaceae family. Considered a hard wood, it is very dense, elastic, resistent to termites, and it is included in the group of woods called imputrecents. Beyond the mechanic properties that form a physical barrier of protection, there is a chemical barrier produced by vegetal tissues, which have fungicide, insecticide and bactericide effects. Lectins constitute a heterogeneous group of proteins from nonimmune origin, differing from each other with respect to their molecular structures, carbohydrate-binding specificities and biological activity. The aim of this work was to identify and isolate M. urundeuva leave lectin (MurLL). The chosen extract (10%, w/v) was prepared in 0.15 M NaCl by 16 h at 4 ºC. The extract was treated with ammonium sulphate in different concentrations (0-20%, 20-40%, 40-60% and 60-80%). Hemagglutinating activity (HA) from fractions was evaluated with human (types A, B, O and AB) and rabbit erythrocytes. The 60-80% fraction (F60-80%) was used to isolate the lectin since it showed the highest specific HA (SHA, 22,339). Inhibition assay of HA from F60-80% was performed with carbohydrates (galactose, glucuronic acid, manose, metil-α-glucopiranoside, metil-α-manopiranoside, N-acetyl-glucosamine, rhamnose, raffinose sucrose, threalose and xylose) and glycoproteins (asialofetuin, azocasein, casein, fetuin, ovalbumin and thyroglobulin). To isolate the lectin a chitin column equilibrated with 0.15 M NaCl was used; protein elution was performed with 1.0 M acetic acid. HA of MurLL was characterized for variation of temperature (30-100 ºC) and pH (3.0-12.0). The highest HA of F60-80% was obtained with human (types A and O) and rabbit erythrocytes (titer of 524,288^-1). HA of MurLL was mainly inhibited by glycoproteins; asialofetuin was the best inhibitor. The chromatographic profile of chitin column showed a unique active (titer of 1,024^-1) protein (3.8 mg) peak after elution with 1.0 M acetic acid. HA of MurLL was detected after 5 h in all evaluated temperatures and was stimulated in pH 3.0. In conclusion, leaves of M. urundeuva  contains a stable lectin that can be isolated in milligrams quantities.