Paulino signed as a non-drafted free agent with the Pittsburgh Pirates organization on December 29, 1997, at the age of 16. In 2002, he was selected by the Kansas City Royals in the Rule 5 draft, but he was returned to the Pirates in spring training of the following year. After making his major league debut in September 2005 with the Pirates, Paulino was selected to the Dominican Republic team for the 2006 World Baseball Classic as a backup catcher. The highlight of the World Baseball Classic for Paulino came on March 13, when Paulino started at catcher against the Cuban team. Paulino went 2–2 with a double, three walks, and a run scored in the Dominican's triumph over Cuba. On April 16, 2006, Paulino was recalled to the Major Leagues and quickly became the Pirates every day catcher. Eventually he was again demoted to Triple-AIndianapolis, as management would give Ryan Doumit the bulk of playing time behind the plate with the Pittsburgh Pirates. Paulino was praised by the Pirates pitching staff as an excellent catcher to work with. The staff earned run average was markedly better when Paulino was behind the plate. His.310 batting average made him the first rookie catcher since Mike Piazza to play in at least 100 games and bat at least.310. He is only the second rookie catcher since 1969 to have those numbers.
Florida Marlins: 2009–10
On December 10, 2008, Paulino was traded to the Philadelphia Phillies in exchange for minor league catcher Jason Jaramillo. He was then traded to the San Francisco Giants on March 27, 2009 for pitcher Jack Taschner. Two hours later he was traded to the Florida Marlins for pitcher Hector Correa. With the Marlins, Pauline platooned with left-handed hitting catcher John Baker. After Baker suffered a season-ending injury in May 2010, Paulino took over starting duties for the majority of the season. On August 20, 2010, Paulino received a 50-game suspension for violation of baseball's drug policy. Paulino claimed the positive test was a result of a dietary pill.
New York Mets: 2011
In December 2010, the New York Mets signed Paulino to a one-year contract. On May 1, 2011, in a game against the Philadelphia Phillies, Paulino went 5–7 and hit the game-winning RBI in the 14th inning in his first game as with the Mets. With the news of the death of Osama bin Laden, the al-Qaeda leader who was the mastermind of the September 11 attacks circulating during the game against their rivals, Mets manager Terry Collins said that Paulino delivered "a good win for us, and obviously a huge win for America tonight." On June 8, Paulino hit his first home run with the Mets, a three-run home run off of the Milwaukee BrewersKameron Loe. Paulino became a free agent after the Mets decided not to tender his contract.
Baltimore Orioles: 2012
The Baltimore Orioles signed Paulino to a minor league contract on January 30, 2012. He also received an invitation to spring training, but arrived three weeks late to camp after having visa issues. Paulino made the Orioles 2012 Opening Day roster after Taylor Teagarden, newly signed by the team to be the backup catcher, went on the disabled list because of back problems. In the second game of the 2012 season, Paulino made his first start of the year as the DH and went 4–4. On July 15, 2012, Paulino was optioned to Triple-A Norfolk to make room for Taylor Teagarden, who was coming off from the 60-day disabled list.
In August 2013, the Orioles assigned Paulino to the Toledo Mud Hens, the Detroit Tigers Triple-A affiliate. He re-signed with the Tigers in November 2013 to fill minor league organizational depth. On February 12, 2014, Paulino was suspended 100 games by Major League Baseball for a second PED-related offense. On July 19, 2014, Paulino was released.
