A process to make ethylene and/or propylene from methane comprises preparing a gaseous mixture of carbon monoxide and hydrogen from methane, performing a Fischer Tropsch synthesis using the gaseous mixture to obtain a Fischer Tropsch product having a 50 wt % recovery point above 250.degree. C., evaporating a part of the Fischer Tropsch product in the presence of a dilution gas comprising the unconverted carbon monoxide and hydrogen from the Fischer Tropsch synthesis step and carbon dioxide into a gas and a liquid fraction and separating the liquid fraction from the remaining gas fraction, further heating the gas fraction and subjecting the gas fraction to a thermal cracking step, isolating a mixture of methane, carbon monoxide and hydrogen from the cracked gases, and recycling the mixture of methane, carbon monoxide and hydrogen to the step of preparing a gaseous mixture.