Madsen grew up in Los Angeles and studied film theory at the University of California, Santa Barbara.
He started at his college to learn poker and played before his WSOP victory in Indian casinos in Santa Ynez.
In the World Series of Poker 2006 he won at the age of 21 years and five weeks, his first bracelet in a Texas Hold'em tournament and was thus six weeks younger than the previous record holder. Only six days later, he won his second bracelet in a $ 5,000 tournament with prize money of more than $ 640,000. He has an unprecedented result in the WSOP 06 delivered by other top 3 results in a Seven Card Stud tournament and Omaha Hold 'em tournament. Thus, he was elected to the World Series of Poker 2006 Player of the Year.
Full Tilt Poker took Jeff Madsen after the World Series immediately at the Full Tilt Pros to.
To date, he has won $ 1,675,000 in poker tournaments.