The available literature on the biology of the European Polecat (Mustela putorius) is collated. Aspects covered are general biology and systematics, distribution, physical characteristics, variation, skeletal characteristics, habitat, general behaviour, diet and predatory behaviour, breeding, juvenile development, population structure, mortality, parasites and diseases, relations with man, and history in Britain. Notes on field signs are also included. Recent and current research on Polecats both in Great Britain and on the European continent are then reviewed and some new information is reported. An extended bibliography lists all major and many minor publications on M. putorius, together with selected references to feral Ferrets (M. furo) and Polecat‐Ferrets (M. putorius x M.furo).