β-Ga2O3 intergrowths have been revealed in the SnO2 rutile structure when SnO2/Ga2O3 complex nanostructures are grown by thermal evaporation with a catalyst-free basis method. The structure is formed by a Ga2O3 nanowire trunk, around which a rutile SnO2 particle is formed with [001] aligned to the [010] Ga2O3 trunk axis. Inside the SnO2 particle, β-Ga2O3 units occur separated periodically by hexagonal tunnels in the (210) rutile plane. Orange (620 nm) optical emission from tin oxide, with a narrow linewidth indicating localised electronic states, may be associated with this β-Ga2O3 intergrowth.