A repeaterless bidirectional wavelength-division-multiplexing (WDM) transmission system for delivery of AM-VSB CATV analog video signals over conventional single-mode fiber (SMF) is demonstrated for the first time. Two kinds of multiplexers, the optical circulator and the WDM multiplexer configurations, for supporting bidirectional operation are used and compared. Satisfied system performance is achieved over a 50-km SMF link. Extending the repeaterless bidirectional transmission distance is also addressed. This technology will play an important role in the shortest fiber link for trunk delivery of any two multiple system operators (MSO's) across another CATV-operator system.