Memdock is a tool for docking α-helical membrane proteins which takes into consideration the lipid bilayer environment. Given two α-helical membrane located protein molecules, the method outputs a list of potential complexes sorted by energy criteria. The program includes three steps: docking, refinement, and re-ranking of the results. All three docking steps have been customized to the membrane environment in order to improve performance and reduce program run-time. In this chapter, we describe the application of our web server, referred to as Memdock, for prediction of the docking complex for a pair of input membrane protein structures. Memdock is freely available for academic users without registration at http://bioinfo3d.cs.tau.ac.il/Memdock/index.html.