A maid found the bodies of the two men, who are believed to be aged 31 and 27-years-old respectively, slumped in a room in the Park Plaza, a hotel in one of main the tourist drags of the Thai capital late Thursday.
Their bodies were found alongside an unknown white powder and drug taking paraphernalia.
"At the initial autopsy the forensic doctor said they died from a drug overdose," the tourist policeman, who wanted to remain anonymous told AFP, adding tests will be carried out on the powder.
Thailand's reputation as a tourist paradise has been tarnished recently after the deaths of several holidaymakers including two Canadian sisters on the resort island of Phi Phi in a suspected poisoning case in June.
In August, a British and a French tourist died in a nightclub blaze on Phuket island in another blow to Thailand's image -- already tarnished over recent years by deadly political unrest, devastating floods, and concerns about violent crimes against foreigners.