This work aims to modify wood using dilute geopolymer suspensions for improving its decay resistance, leachability, mechanical properties and fire resistance. Scots pine (Pinus sylvestris) sapwood specimens were impregnated with either 1, 3 and 5% geopolymer suspensions. The 3% and 5% geopolymer treated wood specimens presented lower mass loss caused by the decay fungus Coniophora puteana than control specimens, while 1% treatment increased the mass loss significantly. The geopolymer suspensions did not affect the mechanical properties of the sapwood specimens. The pine sapwood treated with geopolymer and subjected to leaching displayed the same mass loss to that of the control specimens exposed to leaching. This suggests that the dilute geopolymer suspension leached out from the wood. The geopolymer-suspension-impregnated wood presented an increased time to ignition compared to controls in the fire resistance test, but also a higher amount of smoke released. Results indicate that modification of wood using dilute geopolymer suspension is promising, but presents drawbacks that need to be addressed, such as leaching.