Graphene holds great promise in wide-ranging applications due to its novel electronic, thermal, mechanical, and chemical properties. In many applications, graphene needs to be integrated with other materials, it is thus important to understand the surface physics and chemistry of graphene. Understanding the adsorption behavior of organic molecules on graphene is an important issue to develop the full potential of graphene-based organic electronic devices. This article reviews the interfacial morphologies and electronic structures between organic molecules and graphene, prepared on different substrates. Generally, adsorption of organic molecules on graphene exhibits two important characteristics: (1) formation of well-ordered organic layers based on the graphene template and (2) occurrence of charge transfer between adsorbed molecules and graphene, offering the promise in tuning the electronic properties of graphene. (c) 2013 Elsevier Ltd. All rights reserved.