Recent advances in gas hydrate research mainly focus on dual function gas hydrate inhibitors (DF-GHIs). DF-GHIs exhibit dual behavior of shifting the hydrate dissociation curve to lower temperatures and higher pressures as well as hindering or delaying the nucleation. The main focus of this review is to discuss all the possible factors that can induce dual functionality in gas hydrate inhibitors (GHIs). In this regard, this review summarizes the latest developments, classification, evaluation techniques and experimental findings of GHIs. The experimental data of different research groups is critically analyzed and systematically evaluated in terms of average depression temperature (Delta T) and relative inhibition power (RIP). The Delta T and RIP is calculated from existing experimental data. The studies in this field will give more knowledge at both academic and industrial level for the development of economical, efficient and biodegradable DF-GHIs. (C) 2018 Elsevier B.V. All rights reserved.