Process for the conversion of synthesis gas to higher hydrocarbons. A gaseous stream comprising synthesis gas is contacted at an elevated temperature and pressure with a suspension comprising a particulate Fischer-Tropsch catalyst suspended in a liquid medium, in a reactor system comprising at least one high shear mixing zone and a tubular loop reactor. The suspension and the gaseous stream are passed through the high shear mixing zone(s) wherein the gaseous stream is broken down into gas bubbles and/or irregularly shaped gas voids. Suspension having gas bubbles and/or irregularly shaped gas voids dispersed therein is discharged from the high shear mixing zone(s) into the tubular loop reactor, the discharged suspension is circulated around the tubular loop reactor, and a product suspension stream comprising at least a portion of the circulating suspension is withdrawn from the tubular loop reactor.