The 55-year-old doctor, who worked at a clinic in Barcelona, was arrested Monday, police said. His name was not released.
He is being held until he can appear before a judge, police said.
Regional and municipal police launched an investigation last month after a patient filed a complaint against the doctor. Police said several patients had accused the doctor of sexual abuse but would not confirm how many women had filed official complaints.
As part of the investigation, police searched medical records and interviewed approximately 30 patients, the Barcelona daily La Vanguardia reported.
Many of those interviewed said the doctor told nurses to leave the room during gynecological examinations and used inappropriately colloquial language, according to La Vanguardia. Some patients also accused the doctor of removing his gloves during examinations, La Vanguardia said.
The Catalan Institute of Health has launched an internal investigation and also is collaborating with police, an official at the agency's press office said.