The pulsed field gradient-nuclear magnetic resonance diffusion technique has an appreciable potential for biophysical investigations in membrane biology, various lyotropic liquid crystals, and other complex fluid systems. In particular, topics like transport of molecules both across and within the plane of a lipid membrane can be successfully studied, as well as the formation of lipid domains and their intrinsic dynamics. The pulsed field gradient-nuclear magnetic resonance technique and the preparation of oriented samples for investigations of lipid lateral diffusion in macroscopically aligned bilayers, oriented by a goniometer probe in the main magnetic field, are described. Some recent results illustrating the potential of the method in detecting and characterizing domain formation are also presented.