The envelope glycoprotein G of the Indiana serotype of vesicular stomatitis virus was modified not only by palmitylation, but also by myristylation, both occurring at the carboxy-terminal segment. When infected Chinese hamster ovary cells were grown in medium containing [H-3]-myristate, the G protein and Ga2, the membrane-anchoring fragment containing about 71 amino acids, were labeled. This was shown by immunoprecipitation of cell lysates or extracellular fractions of infected cultures. Thin-layer chromatography of the fatty acid fraction released from G by hydrochloride hydrolysis showed that myristate, per se, was bound to G. The sensitivity of the fatty acid linkage to KOH/methanol indicated that [H-3]-myristate was linked to the protein via ester or thioester bond(s). In contrast, the G protein of New Jersey serotype was not myristylated.