A process for treating a gas stream to remove or recover a condensable component. The process involves a condensation step and a membrane concentration step. The condensation step may be followed by the membrane step, or vice versa. The process can be designed to yield only two product streams: one, the condensed liquid, ready for use, reuse or discard, and two, a residue gas stream, which in most cases will be clean enough for direct discharge or reuse. This result is achieved by recycling other streams within the process. Recovery of 90% or more of the condensable component can be achieved. The process offers substantially energy savings compared with condensation alone.