Plastic deformation properties of icosahedral Al-Pd-Mn single quasicrystals have been measured over a wide range of temperature in constant strain rate experiments including stress relaxation tests. The properties are different in the low and high-temperature ranges. At low temperatures, the deformation is controlled by the lattice friction of the gliding dislocations and a very effective work-hardening mechanism. At high temperatures, the deformation properties are discussed in terms of recovery-controlled plastic deformation.