An endoscope having circumferential surgical instrument positioning capability includes an operation portion an elongated, flexible insertion portion extending from the operation portion a viewing conduit extending through the operation portion and the insertion portion a plurality of instrument channels provided in and spaced around a circumference of the insertion portion and a channel selector sleeve assembly having a selector channel rotatably carried by the operation portion. The selector channel of the channel selector sleeve assembly registers with the plurality of instrument channels, respectively, as the channel selector sleeve assembly is rotated with respect to the insertion portion.