High-aspect-ratio nanostructures were replicated by injection compression molding. The effects of the mold temperature and pattern shape on the degree of replication were investigated using a replication technique for optical disks (digital versatile disks) and a Ni stamper with patterns with a width and height of 200 and 400 nm. A higher mold temperature and a smaller area-duty ratio (hill area/unit area) of the Ni stamper, i.e., a larger area-duty ratio of the replica resulted in better replication because a Ni stamper with a smaller area-duty ratio suppresses the formation of a skin layer.