The count of Royal Bengal tigers will be conducted in wildlife preserves and forests across the Terai Arc region that spans 600 miles across the Indian states of Bihar, Uttar Pradesh and Uttarakhand and into southern Nepal.
The World Wide Fund for Nature, also taking part in the survey, estimates there are around 500 tigers making their home in the region.
Hundreds of camera traps along wild paths used by the tigers will capture images to allow tigers who come into the cameras' range to be identified, officials said.
"The same tiger trapped by a camera here on the Nepali side could cross over into India, but that tiger will be trapped by another camera there," Megh Bahadur Pandey, the director general of Nepal's Department of National Parks and Wildlife Conservation, told the BBC.
The photographic evidence will keep tigers from being counted twice, he said.
The survey is part of a plan unveiled in 2010 with a goal of doubling by 2012 the wild tiger population that has been decimated by habitat destruction and loss of prey, officials said.
"The results will show whether we are succeeding or failing towards that goal," Anil Manandhar of the WWF Nepal program said.