Tanya Robin Hollander, 36, of Rhinebeck, N.Y., admitted she conspired to violate the travel act, which prohibits crossing state lines to further an illegal business.
Hollander, who worked as a booker for the Emperors Club VIP, told the court she began looking for work early last year to supplement her job as a holistic health counselor.
She said she began working for the service in June 2007, arranging dates between hookers and customers at various locations in the United States and Europe.
U.S. District Court Judge Deborah A. Batts asked Hollander if she knew what she was doing was against the law. "It became apparent," Hollander said.
With the plea, she became the last of four club employees arrested in March to admit a role in the illicit business. Prosecutors haven't revealed whether Spitzer will be charged in the probe that began last summer after a series of suspicious banking transactions.
Spitzer resigned March 12 after he was identified as "Client-9," whose meeting with a prostitute known as "Kristen" in a Washington, D.C., hotel the night before Valentine's Day was outlined in an affidavit filed in connection with the case.
In June, Emperors Club VIP operator Mark Brener, 62, of Cliffside Park, N.J., pleaded guilty to conspiracy to commit a prostitution offense and conspiracy to commit money laundering.
That same month Brener's former girlfriend, 23-year-old Cecil Suwal, pleaded guilty to money laundering, conspiracy and conspiring to promote prostitution, admitting her role as a manager of the company.
In May, Temeka Lewis, a booking agent for the escort service, pleaded guilty to promoting prostitution and money laundering.
All three are awaiting sentencing.
Hollander does not have a cooperating agreement with the U.S. attorney's office, and faces up to five years in prison.
Her lawyer, Michael Farkas, called Hollander "a good and decent person" who played a minor role in the scandal.
She is scheduled to be sentenced Nov. 25, and remains free on personal recognizance bond.
By Associated Press Writer Adam Goldman