Physical and mechanical properties of eight fast-growing plantation species in Costa Rica. Wood properties of Acacia mangium (Am), Alnus acuminata (Aa), Bombacopsis quinata (Bq), Cupressus lusitanica (Cl), Swietenia macrophylla (Sm), Terminalia amazonia (Ta), Terminalia oblonga (To) and Vochysia guatemalensis (Vg) planted in Costa Rica were determined. Heartwood (HWC), bark (BP) and pith (PP) proportions, specific gravity (SG), green moisture content (GMC), green density (GD) and mechanical properties were evaluated. Heartwood percentage was lower in Aa, Bq, Ta, To and Vg and highest in Cl and Am. Lower PP was measured in Cl, Sm and Bq. The lowest SG values were found in Bq, Vg and Aa while the highest, in To, Am and Cl. The lowest GMCs were measured in Sm, Ta and To while the highest, in Bq and Vg. Highest GD values were detected in Am and Cl, and the lowest, in Aa. Heartwood, SG, GMC and GD varied with tree height in all species. Swietenia macrophylla consistently yielded high values for most mechanical tests. Terminalia oblonga also had high values for mechanical properties. The lowest mechanical properties were recorded in Vg and Bq