Former president Mubarak, 85, and his sons Alaa and Gamal are accused of seizing and facilitating the seizure of more than 100 million Egyptian pounds ($14.37 million) originally allocated for presidential palaces, among other charges.
"I do not agree ... It never happened," he said, sitting behind a wired mesh cage in the court room and wearing a suit.
Mubarak was sentenced to life in prison in 2012 for complicity in the killing of demonstrators in the uprising that toppled him in 2011. He successfully appealed and is facing a retrial on those charges. He is also accused in two other cases of corruption that have yet to come to court.
Mubarak was released from jail last year after winning his appeal. But he is still being kept under house arrest at a military hospital in the Cairo suburb of Maadi, Reuters reported.
Mubarak's successor, Mohamed Mursi, served as president for a year before he was ousted by the army in July after mass protests against his rule. Mursi is also currently facing trial, over charges that include conspiring against the state, inciting violence and a mass jail break in 2011.
Egypt is pushing through with an army plan that could see new presidential and parliamentary elections this year.