Hydrogen and carbon monoxide are separated from a condensate-containing gaseous mixture thereof by using (a) a("first") stripping column (8) to remove the hydrogen content of the CO-loaded methane stream (6) obtained by washing CO from the gaseous mixture, or the vapour portion from a phase separation thereof, ascending a methane wash column (2) and (b) a ("second") stripping column or a flash separator (30) to remove the hydrogen content of the feed gas condensate (9) obtained from the methane wash column (2), or the phase separation. The vapour stream (32) from the second stripping column or flash separator (30) is fed to the first stripping column (8). The liquid stream from the first stripping column and the liquid stream (33) from the second stripping column or flash separator (30) are fed (16, 17 , 19 & 20; 34 to 39) to different locations of a separation column (18) providing a gaseous carbon monoxide product stream (21) and a liquid methane wash recycle stream (3). The process improves the efficiency of the separation by avoiding dilution of the CO concentration of the feed gas condensate (9) with the CO-loaded methane stream (6) which occurs in prior art CO/hydrogen separations using a methane wash.