Paraffins and waxes are produced from a gaseous feed stream comprising hydrogen and carbon monoxide in a Fischer-Tropsch reactor using a fixed bed of reduced Fischer-Tropsch catalyst having cobalt as catalytically active metal. A nitrogen-containing compound is added to the gaseous feed stream in a concentration of up to 10 ppmV and the mixture if fed to the reactor to obtain paraffins having from 5 to 300 carbon atoms. The product is subjected to a hydrogenation step, to obtain a hydrogenated fraction comprising 5 to 300 carbon atoms. The hydrogenated product is separated into C5-C9, C10-C17, and C18-300 fractions. The C18-C300 fraction is separated to obtain one or more first light waxes having a congealing point in the range of 30 to 75° C. and a second heavy wax having a congealing point in the range of 75 to 120° C.