This study evaluates the decay and termite resistance of Scots pine (Pinus sylvestris L.) treated with 4-methoxytrityl tetrafluoroborate (MTFB). Decay resistance tests of unleached samples showed that 2%, 1.5% and 1% concentrations of MTFB (15.4 kg/m(3), 11.1 kg/m(3), and 7.4 kg/m(3), retention levels, respectively) gave less than 2% decay of Postia placenta and concentrations of 2% and 1.5% less than 2% decay of Coniophora puteana. Wood specimens treated with 4-methoxytrityl tetrafluoroborate solutions were not protected against the brown rot fungi after a 14-day severe leaching process, suggesting excessive leaching of the chemical from wood. Treatment with 2% concentration protected against subterranean termites, Coptotermes formosanus Shiraki based on mass losses in both leached and unleached wood specimens in comparison with lower concentration levels. These results suggest that 4-methoxytrityl tetrafluoroborate might be promising to protect wood being used outdoors against termite attack. However, 4-methoxytrityl tetrafluoroborate did not protect wood against fungal decay. Field tests are needed to observe the performance of 4-methoxytrityl tetrafluoroborate treated wood in ground contact.