In the 2003 NBA draft, the 6-foot-7-inch-tall (201 cm) (in shoes),[3] 210-pound (95 kg) point guard/shooting guard was drafted 22nd overall by the New Jersey Nets. In three NBA seasons he averaged 4 points, 1.4 rebounds and 1.1 assists per game. Planinić's three NBA seasons were not notable, with his only distinguishing moment coming in the 2005–06 season, when he hit a spectacular full-court, 77-foot, 3rd-quarter-ending buzzer beater at a home win, on 9 November 2005, against the Utah Jazz.[4]
Planinić's final NBA game was Game 2 of the 2006 Eastern Conference Semi-finals on 10 May 2006 against the Miami Heat. New Jersey would lose the game 89 - 111 with Planinić recording 1 assist and 1 steal. Miami then won the next 3 games and eliminated the Nets from the playoffs.
In the summer of 2006, Planinić and the Nets agreed to a buyout, in which he was sent back to Europe to spend the season with TAU Cerámica of the Spanish ACB League, a team that also featured talented NBA prospect Tiago Splitter. With TAU Cerámica, Planinić won the Spanish Supercup championship in both 2006 and 2007, and the Spanish League championship in 2008.
On 27 July 2013 he signed a two-year contract with Anadolu Efes.[7][8] In January 2014, he hit a long-range buzzer beater in the last second of the game to defeat Olimpia Milano by a score of 61–60.[9] In his first season with the team, he averaged 8.4 points and 3.7 assists, over 23 EuroLeague games. In the summer of 2014, Dušan Ivković was appointed as Efes' head coach, and Planinić lost his place in the team. Despite that, he was still under contract for the 2014–15 season.[10]