Nearly half of them were killed by poachers, the organization reported on Tuesday.
Illegal hunters are decimating endangered wildlife to gather rhino horns and big cat body parts to sell in East Asia, as well as bush meat -- including gorillas, monkeys, lions and pangolins -- to eat.
One-in-seven park rangers across the two regions -- home to many of the planet's richest biodiversity hotspots -- were seriously injured over the same period, either in accidents or in clashes with illegal hunters.
The death toll was slightly higher that the previous July-to-July reporting period, bringing to 871 the total number of wildlife guardians who have lost their lives in the line of duty since 2009, according to the International Ranger Federation (IRF) and the Thin Green Line Foundation, which compile the grim tally.
"Forty-eight rangers of the 107 lost this year were murdered at their place of work," said Sean Willmore, president of the IRF. "Another 50 died in workplace accidents."
"We have to do better in training and equipping of rangers so that they have a greater chance of returning home to their families after patrol," he said.
The World Wildlife Fund will publish a report detailing the findings later this year, and is conducting a similar survey for East Africa, the organisation said in a statement.
"Rangers are the frontline of protecting much of this iconic wildlife," said Rohit Singh, WWF's Zero Poaching Lead, and president of the Ranger Federation of Asia.
"What is shocking is that -- despite their willingness to bear these grave risks to save shared wildlife -- few are receiving fair pay, insurance and adequate training."
In Asia, rangers earn the equivalent of $292 (250 euros) per month, on average, and in Central Africa the monthly pay check is typically $150.
This year saw the murder of Rachel Katumwa, the first female ranger known to be killed while on duty in the Virunga National Park in the Democratic Republic of Congo.
The month before, suspected members of an armed militia group involved in poaching gunned down five other wildlife rangers and their driver.
WWF has called on governments to urgently review and improve the shortcomings that are endangering park rangers.