WEC 43: Cerrone vs. Henderson was a mixed martial arts event held by World Extreme Cagefighting on October 10, 2009, at the AT&T Center in San Antonio, Texas.

[3] The main event was expected to be a WEC Lightweight Championship bout between current champion Jamie Varner and challenger Donald Cerrone.

This was to be a rematch of their bout at WEC 38 which ended in a controversial technical split decision, but Varner was deemed medically unable to return to competition.

[5] Erik Koch was expected to face Wagnney Fabiano at the event, but was forced from the bout with an injury and replaced by promotional newcomer Mackens Semerzier.

[7] Akitoshi Tamura was expected to compete against Damacio Page at this event, but was pulled from the card due to injury and replaced by WEC newcomer Will Campuzano.