Abstract: The present invention relates generally to the field of polyolefin containers. One aspect of the invention is a polyolefin container coated with a gas barrier coating. In particular, the present invention relates to a polyolefin container coated with a gas barrier coating comprising a first layer of hydrogenated amorphous silicon nitride and a second layer of hydrogenated amorphous carbon. The hydrogenated amorphous silicon nitride layer may be deposited on the container, and the hydrogenated amorphous carbon layer may be deposited on the hydrogenated amorphous silicon nitride layer. A further aspect of the invention is a process for coating a polyolefin container comprising the steps of depositing a layer of hydrogenated amorphous silicon nitride on a polyolefin container by plasma-enhanced chemical vapor deposition and depositing a layer of hydrogenated amorphous carbon on the hydrogenated amorphous silicon nitride layer by plasma-enhanced chemical vapor deposition.