Visitor numbers to Sri Lanka dropped to 167,674, down 19.
9 percent over the corresponding period of last year.
Arrivals from the key markets of Germany and India declined sharply.
The numbers landing in April fell 33.6 percent to 33,039 visitors, despite promotional campaigns in India and Europe, Sri Lanka Tourism said.
Sri Lanka had already lowered its forecast for tourism arrivals by 20 percent to 543,877 for the calendar year 2007.
The figure for arrivals from India fell 41.8 percent to 6,858 in April, despite discount packages offered by the national airline, SriLankan, and local hoteliers.
Negative travel advisories from Britain, France and Germany warned holidaymakers to keep away as the 35-year-old conflict escalated.
Arrivals from Germany fell 44.1 percent to 2,628 in April, while the number of Britons slipped 13.
7 percent to 6,459 in the same month.
The number of holidaymakers was expected to decline further after the government this month shut down the airpo