Isolated clashes continued after the midnight (2200 GMT) deadline for the Nato-brokered ceasefire to take effect, but died down about two hours later.
The European Union and the United States welcomed Thursday's deal, which could pave the way for a political agreement to give the Albanian minority greater rights within Macedonia.
The BBC's Paul Welsh in the Macedonian capital, Skopje, says Western diplomats expect some low level violations of the ceasefire, and the real test will be whether any new large scale confrontations break out.
He says it will take several days of monitoring before Nato is convinced the ceasefire is robust.
Envoys believe it has more hope of success than previous attempts during more than four months of fighting.
But so far the rebels have not agreed to give up their weapons.
In the run-up to the ceasefire, Macedonian helicopter gunships fired rockets at positions occupied by the guerrillas after rebel shells hit the town of Tetovo. Several soldiers and civilians were injured.
Shooting continued after the ceasefire at Radusa, a village near the border with Kosovo, and there were also reports of further shelling around Tetovo.
Guarantees
The government agreed to the ceasefire after receiving guarantees that the guerrillas had signed a separate ceasefire with Nato.
Nato has said that, if there is a lasting ceasefire and significant progress in talks, it will send in 3,000 troops for a month to keep the peace and oversee rebel disarmament.
"We are certainly a lot more optimistic about this one ... it's the first signed ceasefire we have seen," said Nato spokesman Mark Laity.
A truce, struck with the help of the European Union's foreign policy chief Javier Solana on 24 June, is technically already in place, but it has been broken on an almost daily basis.
Nato conditions
Macedonian President Boris Trajkovski's national security adviser Nikola Dimitrov described the new deal as "a major step forward". "We think and we hope this will bring peace to the Macedonian citizens".
German Defence Minister Rudolf Scharping said there was a "realistic perspective" of deployment soon after 15 July, but this depended on the ceasefire becoming a political peace deal.
Nato Secretary-General George Robertson also emphasised that all conditions must be met before troops are sent in.
"We will have to make an assessment when the circumstances are right for a Nato deployment, that is, where there is a ceasefire and a sustainable political settlement," he said.
Constitutional change
A new constitution drafted by French expert Robert Badinter is being considered by
Macedonian and ethnic Albanian politicians.
Our correspondent has been told that an agreement has been struck to allow more official use of the Albanian language in areas with a large Albanian population.
The guerrillas launched their insurgency in February. Despite repeated offensives by the Macedonian forces, they have maintained control over several villages in the north of the country.
The conflict has sparked a flood of refugees over Macedonia's borders, into Kosovo and southern Serbia.
We are certainly a lot more optimistic about this one ... it's the first signed ceasefire we have seen
Nato spokesman Mark Laity
The ethnic Albanian rebels were persuaded by Nato to sign the agreement because talks between Macedonia's main political parties were said to have been making real progress in the past week, since the arrival of the two foreign envoys.
Macedonia key moments
26 February
Clashes between ethnic Albanians and Macedonian army begin
11 May
Government of national unity formed
11 June
Rebels threaten capital, Skopje
24 June
Nato-backed truce sparks riots outside parliament
5 July
Government and rebels sign Nato-brokered ceasefire
Ethnic Albanians, who comprise up to 30% of the population, are pushing for increased rights, including having Albanian made an official second language.
Related to this story:
Viewpoint: Macedonian identity
(04 Jul 01 | Europe)
Fighting rages in northern Macedonia
(02 Jul 01 | Europe)
Nato approves Macedonia force
(29 Jun 01 | Europe)
The Albanian fund-raising machine
(28 May 01 | Europe)
Analysis: Macedonian truce prospects
(05 Jul 01 | Europe)
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