The Lent Bumps 2004 were a series of rowing races held at Cambridge University from Tuesday, 24 February 2004 until Saturday 28 February 2004. The event was run as a bumps race and is one of the series of Lent Bumps which have been held annually in late-February or early March since 1887. See Lent Bumps for the format of the races. In 2004, a total of 121 crews took part (69 men's crews and 52 women's crews), with nearly 1100 participants in total.
Caius men rowed-over in 1st position retaining the headship, their 3rd successively.
Downing women bumped Emmanuel and Caius to take their first ever women's bumps headship.
The highest men's 2nd VIII for the 5th consecutive year was Caius II.