Ethiopia's ruling party poised to win election
Ethiopia poll tipped to return PM to power
Meles cast his ballot in his native town in the northern region of Tigray, where the ex-rebel leader faces unprecedented opposition from some former comrades-in-arms who are disenchanted with what they say is an increasingly dictatorial rule.
Human Rights Watch has charged that Meles has taken tough measures to avoid a repeat of the "mistakes" that nearly cost him victory in 2005.
It accused the government of "waging a coordinated and sustained attack on political opponents, journalists, and rights activists" in the run-up to the polls.
Birtukan Mideksa, the 36-year-old woman who emerged from the 2005 electoral chaos as Ethiopia's most inspirational opposition figure, is serving a life sentence in jail.
She has often been dubbed "the Ethiopian Aung San Suu Kyi", in reference to Myanmar's detained pro-democracy activist.