Abstract: Viscous petroleum may be recovered from viscous petroleum-containing formations such as tar sand deposits in a process employing a cyclical injection-production program in which first steam is injected and fluids are produced without restriction until live steam production occurs at the production well, followed by steam injection with production throttled until the formation pressure at the production well rises to a value between about 60% to 95% of the steam injection pressure, after which fluid production is permitted without restriction and steam injection is reduced to 50% or less of the original injection rate. The process should be applied to a viscous petroleum formation in which adequate communication exist or in which a communication path is first established.