Shadi Muhammad Mustafa Abd Allah, a 27-year-old of Palestinian origin, was found guilty on Wednesday by the court in the western German city of Duesseldorf of membership of al-Tawhid.
He was accused of plotting attacks on two Jewish restaurants in Duesseldorf and a Jewish community centre in Berlin.
German intelligence officers told the court in evidence that al-Tawhid was linked to Usama bin Laden's al-Qaida network, blamed for the 11 September attacks in the United States.
Abd Allah had admitted a role in planning the attacks, and prosecutors asked for half the maximum 10-year sentence because of his admissions.
Next year, he is due to appear as a prosecution witness in the trial of four fellow al-Tawhid members.
Al-Tawhid's stated aims include overthrowing the state of Jordan and death to all Jews.
Zarqawi is alleged to be the link
between al-Qaida and Saddam
According to Germany's BKA federal crime office, its operational leader is Abu Mussab al-Zarqawi, named by the United States as a key link between ousted Iraqi leader Saddam Hussein and al-Qaida.
Abd Allah said al-Tawhid members in Germany were ordered by superiors a day after the 11 September attacks to bomb Jewish sites in Germany.
Prosecutors said his task in the operation was to "find appropriate targets and procure weapons."