Qua sotto trovate un articolo della bbc che approfondisce il tutto.
A coffin with "Sata is dead" on the side was taken to the ceremony
"This is not the time to settle scores. Let us all be united to build Zambia," he said after his re-election.
His closest challenger Michael Sata has claimed massive fraud and said he was the rightful winner.
Mr Sata's supporters have staged two days of violent protests, mostly in poor districts of the capital, Lusaka, where the army has been deployed.
Mr Mwanawasa gained 43% of the vote, while Mr Sata got 29%.
The other main candidate, Haikande Hichilima, won 25% to come third.
Speaking in the National Assembly, Mr Mwanawasa said the people had spoken with a clear voice.
"They want a general improvement of their lives... We have to fight poverty and we have to fight all vices that are affecting our country."
Mr Sata said he would make life difficult for Mr Mwanawasa "inside parliament and outside parliament".
He has alleged voter fraud, saying as many as 400,000 votes appeared not to have been counted in areas where he had expected to do well.
He told the BBC there was lots of time to investigate the ballot: "Levy Mwanawasa's term of office does not come to an end until January, 2007.
"We have... three months in which we can clear all of these things and we have [a situation] where all of the presidential candidates are satisfied."
Electoral Commission President Justice Ireen Mambilima said she was investigating complaints from both Mr Sata's Patriotic Front and Mr Hichilima's United Democratic Alliance.
Mr Mwanawasa's Movement for Multiparty Democracy (MMD) has also won a narrow majority in parliament, with 72 of the 148 contested seats.
The president also nominates eight MPs, meaning his party will have 80 seats - just over half of the 158 MPs.
The PF won 46 seats, while two by-elections will be held following the deaths of candidates.
In Lusaka on Monday, protesters threw stones at police who responded with teargas and by firing live ammunition into the air.
Looting of shops owned by MMD supporters has been reported in parts of Lusaka.
Clashes initially broke out on Sunday in Lusaka when the electoral commission announced that Mr Sata had fallen from first place to third in interim vote counts, as results from rural areas arrived.
The violence and allegations of irregularities contrast with the voting on Thursday, which international observers praised as being generally efficient and transparent.
Since being originally elected in 2001, Mr Mwanawasa has been credited with raising economic growth above 5% and winning Zambia billions of dollars of debt relief.
But the economic reforms have not improved life for most of Zambia's poor, revival in the crucial copper sector has been slow and unemployment is high.Mr Mwanawasa's election victory in 2001 was also accompanied by allegations of fraud.