Abstractβ‐Barrel proteins found in the outer membrane of Gram‐negative bacteria serve a variety of cellular functions. Proper folding and assembly of these proteins are essential for the viability of bacteria and can also play an important role in virulence. The β‐barrel assembly machinery (BAM) complex, which is responsible for the proper assembly of β‐barrels into the outer membrane of Gram‐negative bacteria, has been the focus of many recent studies. This review summarizes the significant progress that has been made toward understanding the structure and function of the bacterial BAM complex.