Prime Minister Nikola Gruevski's centre-right VMRO-DPMNE is far ahead in opinion polls.
One poll gave him 31.3 per cent compared to 11.2 per cent for his nearest rival the Social Democrats.
Gruevski is hoping for a landslide victory in order that he will not have to form a coalition government.
The largest ethnic Albanian opposition party, the Democratic Union for Integration (DUI), was targeted in incidents in and around the western town of Tetovo, Xhevat Ademi, a high-ranking party official said.
"DUI was the target of provocation, of violence, of attacks, but we have never sought to retaliate because we refuse to submit to [violence]", Ademi said.
International monitors have recorded 13 reports of attacks against DUI offices.
Ali Ahmeti, the party leader, was shot at by an unknown gunman on May 12. A bystander was injured in the attack.
Tetovo, a majority Albanian region, is the main battleground between the DUI and its fierce rival the Democratic Party of Albanians (DPA).
Ademi said the DPA was "nervous" because "DUI will win the elections".
But Imer Selmani, the outgoing health minister and vice-president of the DPA, countered that DUI was frustrated at having been out of power for almost two years.
"Our political adversaries are presenting themselves as victims when in fact they never stop raising the threat of a return to 2001."
Ethnic Albanians constitute about 25 per cent of Macedonia's population.
The minority fought a six-month insurgency against state forces in 2001, which was ended by a western brokered peace deal.
Calls for international standards
The European Union and the United States called jointly on Saturday for the elections to be "free from intimidation and in line with international standards".
But Radmila Sekerinska, the 35-year-old leader of the Social Democrats, complained on Saturday of fraud.
She alleged that posters appeared in Skopje, the capital, overnight intending to confuse voters into casting ballots for the wrong party; they mimicked her own posters but gave a different voter list number.
The electoral monitoring mission of the Organisation for Security and Cooperation in Europe (OSCE) has also registered complaints about a small party's voter list containing candidates with remarkably similar names to those on the Social Democratic ticket.
"It was clear that this is a scheme aimed at transferring some of the votes from our list to the governing list," Sekerinska said.
Nato entry blocked
The Balkan state had its entry to the Nato blocked in April by neighbour Greece after a dispute over Macedonia's name.
This added to a political crisis that led to the elections being called two years early.
Greece refuses to allow Macedonia to join Nato or the EU unless it changes its name, which Athens says implies claims on its own northern province of Macedonia.
Unlike the Social Democrats, Gruevski has rejected a name change and has vowed to put the issue to a referendum.
The mainstay of Gruevski's campaigning has focused on national pride and the name issue.