The search for extrasolar transiting planets requires high accuracy photometric observations over a long time basis. The method therefore favors observing sites allowing for long uninterrupted observations, or observations with space satellites. The first space mission searching for planetary transits is the French-led CoRoT mission launched in December 2006. Its longest observing sequences span 150 days, whereas Dome C can provide a ground-based site for observations over 2–3 months. Full observational coverage of at least three transit events up to about two weeks orbital period can be obtained from Dome C during one winter season when realistic conditions for cloud coverage are taken into account. The efficiency can be further optimized if Dome C is combined with other sites at low-latitudes, closing the gap of the summer break in Antarctica.