The coat protein I (COPI) complex is considered to be one of the best-characterized coat complexes. Studies on how it functions in vesicle formation have provided seminal contributions to the general paradigm in vesicular transport that the ADP-ribosylation factor (ARF) small GTPases are key regulators of coat complexes. Here, we discuss emerging evidence that suggests the need to revise some long-held views on how COPI vesicle formation is achieved.