AMPA-type glutamate receptors mediate the majority of fast excitatory transmission in the central nervous system. The trafficking of AMPA receptors to and from synapses alters synaptic strength and has been recognized as a central mechanism underlying various forms of synaptic plasticity. Both secretory and endocytic trafficking events seem to be driven by the subunit composition of AMPA receptor tetramers. Moreover, recent work suggests that synapses employ different tetramer combinations in response to altered synaptic input, suggesting the existence of signalling pathways that mediate remodelling of AMPA receptors. These latest developments and recent progress in elucidating the mechanisms that underlie channel assembly and trafficking are the subject of this review.