Zanu-PF is accused of rigging the election
The presidents of Kenya, Zambia and Tanzania fully backed Mr Mugabe, Namibia called the vote "watertight, without room for rigging", while South African and Nigerian leaders gave more qualified assessments.
South Africa is facing the dilemma of how to handle its chaotic northern neighbour without provoking instability in the region, and retain the credibility of an African renaissance plan.
President Thabo Mbeki said he could not comment finally until all observer reports were in.
But South African and Nigerian observers have said the official results reflect the will of the electorate.
Analysts say most African leaders will not condemn the electoral process in Zimbabwe for fear that it may backfire when they next hold elections at home.
Some comment that African leaders are presenting a united front in protest at what they see as Western attempts to impose Western democracies on Africa.
Commended
The Organisation of African Unity (OAU) observer team in Zimbabwe announced that "in general the elections were transparent, credible, free and fair."
"The team wishes to commend the electoral and polling officers for the able manner in which they conducted the elections," leader Gertrude Mongella said.
A team from the Southern African Development Community (SADC) Council of Ministers has issued a statement saying that the vote had been "substantially free and fair" and has asked the heads of state of SADC countries to support the government of Zimbabwe to facilitate dialogue and reconciliation.
But a team from the SADC's Independent Parliamentary Forum, said the ballot "did not conform with (its) norms and standards".
And significantly, the Commonwealth observer group, led by former Nigerian leader Abdulsalami Abubakar, harshly condemned the vote saying it did not reflect the will of the people and was held in a climate of fear.
"The conditions in Zimbabwe did not adequately allow for a free expression of will by the electors," he said.
'Will of the people'
South Africa welcomed the fact that there had been no significant conflict between the participants.
"President Thabo Mbeki has emphasised that South Africa's primary objective in this period is to work with the government of Zimbabwe, whoever is president, in order to address the critical question of economic reconstruction and urgently to deal with food shortages," said a statement issued by the South African Government.
Mr Mbeki would comment on the outcome once he had received additional reports from observers, it concluded.
The Nigerian Government said it would urge Europe and the United States to join in accepting the results as announced.
An official from President Olusegun Obasanjo's office said: "It seems the elections were not perfect but they reflected the will of the people. The people there are pretty divided".
'High esteem'
Another long-serving and controversial African leader, President Daniel arap Moi of Kenya, was more forthright in congratulating his Zimbabwean counterpart on the result.
"Your victory and that of Zanu-PF is a testimony of the confidence and high esteem the people of Zimbabwe hold in you," Mr Moi said in his message to Mr Mugabe.
Tanzania's President Benjamin Mkapa called Mr Mugabe a "champion of democracy".
"I am pleased to send my warm congratulations on the renewed and the deserved presidential mandate the people of Zimbabwe have given you," he said.
Namibia's Government warmly congratulated President Mugabe.
"It is clear that the people of Zimbabwe have spoken with an unambiguous voice on their choice of leader," said a government statement.
Zambia's President Levy Mwanawasa said he was pleased to learn of the results.
"As chairman of the Organisation of African Unity (OAU) and president of a friendly neighbour, I congratulate President Mugabe on his re-election," Mr Mwanawasa said.