The bomber appeared to be the only fatality, reports CBS News correspondent Robert Berger. Israeli Web sites identified him as a 20- or 22-year-old Palestinian from the West Bank.
Medics said one person was seriously wounded, and four were in moderate condition. Police initially said 20 people were hurt, but later lowered the number.
Islamic Jihad, which has claimed responsibility for each of the other suicide bombings since a truce took effect last February, claimed responsibility for this one.
The attacker blew himself up after entering a food stand selling shwarma, sandwiches made from meat sliced off a skewer, police reported. The area near the bus station is generally crowded with shoppers and travelers.
"This happened in two seconds, he entered the shop, took two steps, and blew himself up," said Ari Sharon, owner of the targeted restaurant, the Mayor's Shwarma.
A witness, who identified himself only as Itzkik, said he was eating at the fast-food stand when he began suspecting the man standing next to him.
"All of a sudden a policeman came, he pulled him (the suspect) out, and started searching him," he told Israel Radio. The suspect fled, Itzik said, and five minutes later the explosion was heard.
Police said the bomber blew himself up in the restaurant's bathroom and may have been trying to prepare the explosive device when it went off prematurely.
The old bus station is in a working class neighborhood, where many foreign workers live. Blood, shattered glass and debris covered the ground near shops. The windows of a parked car near the blast were blown out.
The old bus station has been targeted before. In January 2003, 23 people were killed and about 120 wounded in a double suicide bombing in the area