A method for producing methanol comprises the steps of passing a feed stream of methanol synthesis pas through a main methanol reactor containing a methanol synthesis catalyst, to form a mixed gas containing methanol, cooling the mixed gas containing methanol, separating methanol from the mixed pas and heating the mixed gas. The stream of heated mixed gas is passed through an additional methanol reactor containing a methanol synthesis catalyst, and the effluent from the additional methanol reactor is mixed with the feed stream of methanol synthesis gas and passed through the main methanol reactor.