A case under section 354A (sexual harassment) of the Indian Penal Code was registered at Sushant Lok police station against the Fortis staffer.
The victim was admitted to the hospital on July 5 for treatment.
"She was allegedly sexually harassed during her treatment," Hawa Singh, Assistant Commissioner of Police, told IANS.
The woman was discharged from the hospital on July 15 after which she contacted the Iraqi embassy.
Officials of the Iraqi embassy then contacted Indian officials after which the case was registered.
"The case has been registered on the complaint of Director of Bureau of Security Ministry of External Affairs," Singh said.
"We are checking out the CCTV footage of the hospital when the victim was hospitalized," he added.
Fortis hospital's spokesperson was not available for comment despite several efforts by IANS.