The eight rowers and their cox were taken by lifeboat to Putney, south London, and their sunken boat was recovered and returned to the crew's base later today.
The rescuers later tweeted: "Glad to say all athletes are well and ready to go."
Oxford had been training for the annual Boat Race, which - along with the men's race - takes place on April 11.
Oxford are favourites to win the women's Boat Race but the accident will give a boost to the Cambridge crew, age-old rivals in the traditional boat race.
An RNLI spokesperson said: "While passing through Putney on exercise the crew of the Chiswick RNLI Lifeboat noticed some unusual manoeuvring on the water just beyond Fulham railway bridge.
Christine Wilson, chief coach of the Oxford women's crew, said: "The tideway can be tempestuous, fickle and a challenge for the most experienced navigators, which is why we regard the river as the other competitor in the Boat Race.
This year's race will be the first time the women's race has been contested on the same course, over the same distance, and on the same day as the men's race.
In previous years the women's race has been held at Henley Royal Regatta.
The women's race has been contested since 1927, with the score standing at Cambridge 40, Oxford 29.
