Some structural properties of the vesicular stomatitis virus (VSV) G protein were examined in virions and isolated envelope fragments. We have shown that in the virion a portion of the G protein extends through the lipid envelope and that this part of the molecule can be cleaved by chymotrypsin. Envelope fragments isolated from VSV without the use fo detergents maintained the structural characteristics of the G protein found in intact virions. In addition, we provide evidence that at least some of the isolated envelope fragments have both sides of the bilayer exposed to added reagents, suggesting that this preparation would be useful for in vitro reassociation experiments.