Process intensification is a chemical engineering field which has truly emerged in the past few years and is Currently rapidly growing. it consists in looking for safer operating conditions. lower waste in terms of costs and energy and higher productivity; and a way to reach such objectives is to develop multifunctional devices such as heat exchanger/reactors for instance. This review is focused on the latter and makes a point oil heat exchanger/reactors. After a brief presentation of requirements due to transposition from batch to continuous apparatuses. heat exchangers/reactors at industrial or pilot scales and their applications are described. (C) 2008 Elsevier B.V. All rights reserved.