Washington Wizards (2001–2005)
Originally signing a letter of intent to play for the University of Florida, he later declared for the 2001 NBA draft. The Washington Wizards, under team president Michael Jordan, used their first overall pick on him. Following a pre-draft workout with the Wizards, it had been reported that Brown told then-Wizards coach Doug Collins, "If you draft me, you'll never regret it."
Perhaps as a result of hype and high expectations, Brown's rookie season was marred by a lack of maturity and production on the court. In his rookie year, Brown averaged 4.5 points and 3.5 rebounds per game.
However, the Wizards believed in Brown's potential. In his second season as a professional, Brown saw more action in the league. He started 20 out of the 80 games he played and the total minutes he played doubled.
Brown improved his numbers, posting averages of 7.4 points and 5.3 rebounds per game. In his third season, Brown continued to improve, posting career highs in both points (10.9) and rebounds (7.4). In a game against the Sacramento Kings, he registered 30 points and 19 rebounds.
After his first three years in Washington, Brown rejected a five-year, $30 million contract offer, electing instead to test the free agent market when his contract expired after the season. In his fourth season, Brown was limited to 42 games due to injuries. His highest-scoring game of the season was 19 points, compared to his season-high of 30 the year before, and he averaged 7.0 points per game. Late in the season, criticism increased; he feuded with Gilbert Arenas, other teammates, and his coach Eddie Jordan.