The singer, of Friern Barnet, north London, made her first appearance at London's Southwark Crown Court on Thursday accused of brokering a cocaine deal.
The N-Dubz star is charged with helping an undercover reporter obtain 13.9g (0.5oz) of the Class A drug for £860.
She appeared alongside rapper Mike GLC, also known as Michael Coombs, 35, of Velocity Way, Enfield, north London, for a 10-minute preliminary hearing.
Coombs also denies a charge of supplying the drug on 23 May.
The pair spoke only to confirm their names and say that they understood the current timetable.
A case management hearing will also take place on 27 March.
The trial is expected to last two weeks.
Contostavlos and Coombs were initially arrested in June last year, after The Sun newspaper claimed they introduced undercover reporter Mazher Mahmood, sometimes known as the fake sheikh, to an alleged drug dealer.
After the hearing, a man thought to be Contostavlos's solicitor read a statement to reporters, which said: "Today Tulisa appeared at Southwark Crown Court in connection with a serious allegation that she has been concerned in the supply of drugs.
"Tulisa is not guilty of this, or any other offence, and is looking forward to giving her account to a jury.
"That trial will reveal the full extent of the role played by Mazher Mahmood and the Sunday Sun."