The Provincial Police formed the largest of the TNPD operational components in both manpower and geographic responsibility. It was headed by a commander, who reported to the director general of the TNPD, and administered through four police regions--geographic areas of responsibility similar to those of the army regional commands. This force provided police services to every town and village throughout the kingdom except metropolitan Bangkok and border areas. The Provincial Police thus handled law enforcement activities and in many cases was the principal representative of the central government's authority in much of the country.

During the 1960s and early 1970s, as the police assumed an increasing role in counterinsurgency operations, a lack of coordination among security forces operating in the rural areas became apparent. Observers noted that the overall police effort suffered because of conflicting organizational patterns and the highly centralized control system that required decisions on most matters to emanate from the various police bureaus of TNPD headquarters in Bangkok.

A reorganization of the TNPD in 1978 and 1979 gave more command authority to the four police lieutenant generals who served as regional commissioners of the Provincial Police. Thereafter, the senior officers of each region not only controlled all provincial police assigned to their respective geographic areas but also directed the railroad, highway, marine, and forestry police units operating there, without going through the chain of command to the Central Investigation Bureau in Bangkok. Although this change increased the workload of the four regional headquarters, it resulted in greater efficiency and improved law enforcement.

Data as of September 1987