Mrs Madikizela-Mandela, who denies the charges, arrived at the Pretoria courthouse in a car flanked by bodyguards.
"You're in my way," she told a crowd of cameramen as she entered the building accompanied by her daughter Zindzi, according to Reuters news agency.
The proceedings were adjourned for a day after the judge agreed to a defence request for further information from the prosecution.
The charges against her and co-accused, broker Addy Moolman, involve more than R1m ($100,000), allegedly obtained by fraud through her work for the ruling African National Congress (ANC).
She and Mr Moolman are accused of obtaining bank loans using her signature for fictitious members of the ANC's Women's League, which she heads.
Neither spoke in court, as lawyers embarked on an hour of legal arguments.
More than a dozen members of the ANC Women's League, which Mrs Madikizela-Mandela heads, were in the public gallery to back their president.
This is the latest in a long line of personal scandals to hit 65-year-old Ms Madikizela-Mandela, who continues to enjoy widespread support in the country.
Winnie Madikizela-Mandela
1957
Marries Nelson Mandela
1991:
Convicted of kidnapping Stompie Seipei
1994
Elected as ANC MP and becomes junior minister
1995
Sacked from ministerial post
1996
Divorced from Nelson Mandela on grounds of adultery
2002
On trial for fraud
Ms Madikizela-Mandela, who was divorced from the former South African president in 1996, says she is being persecuted.
'Mugger of the nation'
The BBC's Alistair Leithead says she is still one of the most famous women in South Africa, widely regarded as a champion of the poor.
But the reputation of the sitting MP has been damaged by a succession of scandals which led to the "Mother of the Nation" being nicknamed "Mugger of the Nation".
The most dramatic event involved the murder of a 14 year old boy, Stompie Seipei in Soweto township.
In 1991, she was convicted of kidnapping the young anti-apartheid activist with the help of a group of her supporters, who were part of what was known as the Mandela United Football Club.
A member of the football club was jailed for the boy's murder and Ms Madikizela-Mandela was received a six-year sentence, subsequently reduced on appeal to a fine.
In 1995, she was sacked from her ministerial post in the ANC-led government, and the following year President Mandela divorced her on grounds of adultery.
In February this year, she was evicted from the Soweto house she used to share with Mr Mandela before he went to prison under the apartheid regime. The house is due to become a museum.
Last month, she snubbed a parliamentary committee which had summoned her to explain how she lived a lavish lifestyle on her MP's salary.