AbstractSimarouba versicolor wood was evaluated relative to its kraft pulping ability and compared with Eucalyptus urograndis wood. Comprehensive chemical analysis of wood and milled wood lignin (MWL) was performed, aiming to correlate wood and lignin structural features with kraft pulping response. Wood characterization of S. versicolor revealed higher lignin content (37.3%) and lower cellulose content (45.1%) than E. urograndis. 13C NMR spectroscopy was performed to characterize MWL, and the results showed a lower syringyl to guaiacyl ratio (S/G), higher degree of condensation, and lower β-O-4 linkages for S. versicolor. The gross heating value of S. versicolor was slightly higher than that for E. urograndis. Significant variations were observed in chemical charge demand and in pulping yield for the two species. This behavior was attributed mainly to the S/G ratio and degree of condensation of the lignin, although total and insoluble lignin, as well as cellulose contents may have affected pulping efficiency too.