Mayo and Sligo were among eight Garda divisions where investigations were carried out two days last week as part of Operation Quest - targeting the demand for sexual services and to enforce legislation which criminalises the purchase of such services.
The two days of action last Thursday and Friday were co-ordinated by the Garda National Protective Services Bureau in liaison with local detectives.
Across eight Garda divisions, 23 people were stopped and questioned on suspicion of having purchased sexual services from persons involved in prostitution.
A number of files will now be prepared for the DPP.
This is the third national operation of its kind by Gardai this year targeting the demand for prostitution.