The Kingdom of Siam relinquished its authority over Terengganu to the British Government through the Bangkok Treaty of 1909. However, since Sultan Zainal Abidin III did not assent to the draft of the 1902 Treaty, only British agents were stationed in Terengganu. Although only British agents were intended to be stationed in Terengganu, Sultan Zainal Abidin III did not want to accept the stipulations of the Bangkok Treaty and had taken cautious steps in accepting the placement of British officers. He refused to accept the placement of British agents and examined all the contents of the agreement drafted by the British. This study aims to examine the wisdom of Sultan Zainal Abidin III in dealing with the British Government interference in Terengganu state government affairs with the placement of a British officer of the rank of an agent after the Bangkok Treaty of 1909. This study used a qualitative research method with a historical approach. The results of this study found that Sultan Zainal Abidin III tried to avoid British interference of placing an officer in Terengganu. Although only an agent-ranking British officer was stationed in Terengganu, His Majesty refused to accept the stipulation. When he realised that he ought to accept the British agent in Terengganu, he tried to examine all the contents of the agreement which was aimed at reducing the jurisdiction and influence of the British agent in the administration of Terengganu.