NSF (N-ethylmaleimide Sensitive Factor), first discovered in 1988, is a key factor for eukaryotic trafficking, including protein and hormone secretion and neurotransmitter release. It is a member of the AAA+ family (ATPases Associated with diverse cellular Activities). NSF disassembles SNARE (Soluble N-ethylmaleimide sensitive factor Attachment protein REceptors) complexes in conjunction with SNAP (Soluble N-ethylmaleimide sensitive factor Attachment Protein) adaptor proteins. Structural studies of NSF and its complex with SNARE and SNAP (known as 20S supercomplex) started about twenty years ago. Crystal structures of individual N and D2 domains of NSF and low-resolution electron microscopy structures of full-length NSF and 20S supercomplex have been reported over the years. Nevertheless, the molecular architecture of the 20S supercomplex and the molecular mechanism of NSF-mediated SNARE complex disassembly remained unclear until recently. Here we review recent atomic-resolution or near-atomic resolution structures of NSF and of the 20S supercomplex, and recent insights into the molecular mechanism and energy requirements of NSF. We also compare NSF with other known AAA+ family members.