Of the 7,603 eligible voters, 4,102 voted in favor of joining the international union, according to a National Mediation Board tally.
Continental spokeswoman Julie King said there were about 7,750 operations, ramp and cargo employees at the carrier who will be represented by the union.
The airline's pilots, mechanics and flight attendants are unionized.
Our mechanics are already Teamsters, said Reginald Robinson, a customer service agent who has been with Continental since 1998. We work right beside them, hand to hand. As we're loading planes, they're out there doing service checks on the plane.
Fleet service workers at Continental have tried to unionize several times in the past 12 years but until now could not muster enough votes, according to Robinson, who has been at the helm of the effort to unionize the fleet service group.
Since 1998, the workers attempted to join the International Association of Machinists as well as the Transport Workers Union, Robinson said.
Robinson said Continental's fleet workers first approached the Teamsters three years ago, while still in negotiations with the Transport Workers Union.
They (the Teamsters) decided to decline at the time because they didn't want to step on another union's toes, Robinson said in a telephone interview. But we didn't take no for an answer.
(Reporting by Deepa Seetharaman; Editing by Gary Hill)