1998 saw the 14th edition of the Yamaha Thailand Cup.
It was Thailand's main inter-provincial competition, played between qualifiers from various regions.
The first round saw four groups of four teams, of which the top two sides qualified for the Quarter-Final knockout stage.
Bangkok Metropolitan Administration FC beat Nakhon Si Thammarat FC in the final.
Results
Bangkok Metropolitan Administration FC and Amnat Charoen advance to Quarter-Final stage.
Results
Nakhon Si Thammarat FC and Phetchaburi advanced to the next round
Results
Ayutthaya and Phitsanulok FC advanced to the next round