This document provides guidance on undertaking risk assessment of all microbial hazards which may adversely affect human health in foods along a food chain. This document is also intended to provide practical guidance on a structured framework for carrying out risk assessment of microbiological hazards in foods, focussing on the four components including hazard identification, hazard characterization, exposure assessment and risk characterization. These guidelines therefore represent the best practice at the time of their preparation, and it is hoped that they will help stimulate further developments and disseminate the current knowledge.