Police arrested a Nigerian man on a charge of selling cocaine in the parking lot at Patong Hospital in Phuket on Wednesday.
The suspect was caught in a sting operation that led to his immediate arrest, police said.
Arresting officers seized two small packets of cocaine with a total of 1.10 grams of the drug, purchased for 6,000 baht as part of the undercover buy.
The suspect was charged with unauthorised sale of a category 2 drug (cocaine). He was not named.
He was being held in police custody for further investigation and legal action.