The man, who was identified only as Mr A, 56, was seen riding a scooter on several roads in Pattaya before he stopped at a road on Khao Phra Tamnak and carried out the self-gratification act.
Police were alerted about the naked foreigner when passers-by saw the man riding the scooter. They found the man on Khao Phra Tamnak in Moo 10 village in Tambon Nong Plue, Bang Lamung district.
He was taken to Pattaya Police Station for further legal action.