In an extensive analysis of open-source documents, the Bureau of Investigative Journalism found that 2,292 people had been killed by US missiles, including as many as 775 civilians.
The strikes, which began under President George W Bush but have since accelerated during the presidency of Barack Obama, are hated in Pakistan, where families live in fear of the bright specks that appear to hover in the sky overhead. In just a single attack on a madrassah in 2006 up to 69 children lost their lives.
Chris Woods, who led the research, said the detailed database of deaths would send shockwaves through Pakistan, where political and military leaders repeatedly denounce the strikes in public, while privately allowing the US to continue.
"This is a military campaign run by a secret service which raised problems of accountability, transparency and you have a situation where neither the Pakistanis nor Americans are clear about any agreements in place and where the reporting is difficult," he said.
"All of this means that when things go wrong there is simply no redress for the families of those who have been mistakenly killed."
The research, culled from more than 2,000 news reports, leaked documents and witness statements, show how the drones gradually moved from a rarely used tool, beginning with a single strike in 2004, to a frontline weapon of war.