Rahman Abdulzahra al-Jazairi was near his home in the predominantly Shiite neighbourhood of Jamila in north Baghdad when gunmen opened fire, wounding his father and brother and abducting him, police said.
Jazairi is the general secretary of Hezbollah Warithun, an offshoot of the main Hezbollah party in Iraq.
It is not expected to win any seats in parliament following the April 30 vote, results of which are due to be released later today or tomorrow, election commission officials say.
Jazairi's kidnap is the first incident of its kind since the election, the run-up to which was plagued by attacks on campaign rallies and candidates, but no reported kidnappings.
The election results have been delayed because of a litany of complaints, according to the election commission.
But Iraq's political parties have nevertheless already begun manoeuvring to build alliances in order to get a head start on forming a government.
