The 52-year-old Aunor, popularly known to her fans as "Ate Guy," was arrested at the Los Angeles airport in March 2005 when security agents discovered eight grams of methamphetamine in her handbag.
On Wednesday she entered her plea with Los Angeles Superior Court Judge James Brandlin and agreed to allow probation officers to monitor her progress at a court-ordered drug rehabilitation program, Superior Court spokeswoman Susan Matherly said.
In exchange sentencing will be delayed for 18 months, Matherly said.
After that period, and after she has successfully completed the drug program, the entertainer can ask that the charges be dismissed, Matherly added.
In December, a judge initially suspended criminal proceedings when the entertainer agreed to enter a rigorous drug detoxification program.
But Aunor left that program earlier this month after failing to reach an agreement with another judge over her request to be allowed to travel outside of Los Angeles. Her lawyer said she had complied fully with that program.
The entertainer has upcoming concerts in the US cities of San Francisco, Boston, Washington and in the state of Ohio, her lawyer Claire Espina said.
Aunor, whose real name is Nora Cabaltera Villamayor, has made more than 170 films, many with former President Joseph Estrada. She has also recorded more than 20 albums in both English and Filipino.