Nanofluids have been gradually used as thermodynamic fluids because of their fascinating properties on stability, thermal conduction, thermal convection and boiling heat transfer. Numerous explorations on thermal physical properties, potential benefits and applications have been expanded explosively. A multitude of reviews have attempted to provide comprehensive summaries on preparation, properties, heat transfer and applications performance of various nanofluids, which have become quite difficult because of the tens of thousands of related literatures. Therefore, a selective and comprehensive summary on a certain aspect of a certain nanofluid will instead be of considerable value. This review concentrates on heat transfer characteristics of TiO2 nanofluid since it has been considered as one of the closest kinds to the practical application owing to its comprehensive properties such as sensational dispersivity, chemical stability and non-toxicity. At last, this review identifies the challenges and opportunities for the future study. It is expected that this review can provide a comprehensive exhibition of research progress in the heat transfer applications of TiO2 nanofluids. (C) 2016 Elsevier Ltd. All rights reserved.