Organosolv pulping of fungally pretreated samples of Pinus radiata was evaluated. A screening study using ®ve white-rot fungi indicated that Ceriporiopsis subvermisopora and Punctularia artropurpurascens were the most selective ones for lignin degradation. These fungi were further cultured in bioreactors containing 2.5 kg of wood chips. Fungally-pretreated samples were deligni®ed by formic acid/acetone (7:3) at 150 °C. Pulping kinetics and strength properties of the resulting unbleached pulps were evaluated. Deligni®cation rates and xylan solubilization rates were higher for the decayed samples than for the undecayed control, except for the sample biotreated with P artropurpurascens for 30 days. C subvermispora proved appropriate for treating the wood samples before organosolv pulping, since pretreatment with this fungus resulted in faster wood deligni®cation and pulps with lower residual lignin. Increases in tensile index ranging from 3% to 22% were observed for most pulps prepared from biotreated samples, independently both of the fungal species used in the pretreatment and of the extent of the wood biodegradation expressed as wood weight loss. However, tear and burst indexes and brightness were lower than or similar to those of pulps prepared from the undecayed control.