Changi Airport handled 4.49 million passengers in March, 2.5 per cent fewer than a year ago.
Thailand's political instability and fewer Chinese tourists visiting South-east Asia in the wake of the disappearance of Malaysia Airlines Flight MH370 a month and a half ago were some reasons for the traffic dip.
About two-thirds of the passengers on board the Malaysia Airlines flight which vanished on March 8 and remains lost were Chinese nationals.
Total passenger traffic for the first quarter of the year hit 13.2 milion, or 1.1 per cent more compared to the January to March period last year, Changi Airport Group said on Thursday.
There were 29,100 landings and take-offs, a 2.5 per cent increase over the same month last year.
Between January and March, 86,300 flight movements were recorded, a 4.5 per cent year-on-year jump.
On the cargo front, 169,800 tonnes were processed in March, a slight decline of 1.3 per cent over a year ago.