Ancient records reveal that before establishment of the current dynasty in the late 18th century, the area called Phangnga was a district attached to Takuapa, the leading town thereabouts. Then with the beginning of the Rattanakosin Dynasty, during the reign of Rama l, Phangnga was given equal status with Takuapa and another nearby town, Takuatung, and all three were removed from the government's Harbour Department and put under the Ministry of Defence.

Evidence indicates that Phangnga was officially established in 1789 during the reign of Rama ll, when one of the periodic wars with Burma was raging. The king there, Padung Kasatri, appointed Ah Terng Woon to lead an invasion force to attack Siam's southern towns. The ship-borne army carried off the populations of Takuatung, and Talang (in Phuket). Talang was razed to the ground. An army under the direction of a royal prince was therefore sent from Bangkok to drive off the attackers.

While the war was raging some of the local people took refuge at a place then called Kra Pu-nga*(Malay for river mounth of Pu-nga) protected on all sides by mountains. After the razing of Talang, it was the government's view that Thailand's hold on the area had weakened, and that a new town should be established to reinforce central control. Thus the citizenry left in the Talang area was instructed to move to Kra Pu-nga and register themselves as being resident there. There is still a village in what is today Takuatung District called Talang founded by those immigrants from Phuket. The new city was put under the administration of the government in Nakorn Sri Thammarat.

During the reign of Rama ll., the central government thought to strengthen the southwest coastal towns that were prey to successive Burmese attacks, by appointing a governor for the province who reported directly to Bangkok. Praya Borirak Puton (Sang Na Nakorn) thereby became first governor of Phangnga in 1840. In the same year, Takuatung was reduced in status and became merely a district of Phangnga.

Throughout this period tin mining was booming, and as one of the most tin-rich of Thailand's tin bearing locales, Phang-Nga attracted increasing attention from the central government because of tin's importance as a foreign exchange earner.

One of Phang-Nga Town's most beautiful old buildings is the Provincial Hall. The first such structure was built in Baan Chai Kai: a larger one was constructed in 1930 at Baan Tai Chang. The present structure near Poong Chang Cave was built in 1972.

*Pronunciation of Phang-nga's name is thought to have resulted from foreign tin buyers' and operators' confusion with the way it was formerly written on maps, Pu-nga - in which the old long 'oo' sound is not clearly expressed. If pronounced with a short'oo' it is very close to the present pronunciation.