One Thai woman was killed and 20 injured, including foreign tourists, when the second bomb exploded near Raintree beer bar at Yak Selakram in Hua Hin district of Prachuap Khirikhan at about 11.10 pm.
While the first bomb went off 50 metres away about an hour earlier from the second bomb but caused no harm to anybody.
Hua Hin chief district officer Suthipong Klai-udom said that the bomb detonated by mobile phone which was hidden near plant pot.
Entertainment venues in Hua Hin were ordered to close following the bomb blast.
EOD officers were at the scene to inspect the incident.