In a report released on Wednesday, HRW said Washington was just one of many governments that had sent suspects to a country where suspects could be held incommunicado for a prolonged length of time.
The group says Cairo has also refused to acknowledge the whereabouts of suspects or even confirm they were in custody – a fact they say raises concerns that some of the suspects have "disappeared".
The 53-page report, called Black Hole: The Fate of Islamists Rendered to Egypt, identifies about 60 individuals, mostly alleged Islamist activists of Egyptian origin, whom other states have "rendered" or sent to Egypt since 1994.
The sending states have mainly been Arab and South Asian countries, but include Sweden as well as the United States.
"Sending suspects to a country where they are likely to be tortured is strictly prohibited under international law," said Joe Stork, deputy Middle East director at HRW.
"Egypt's terrible record of torturing prisoners means that no country should forcibly send a suspect there."
The group adds that transporting suspects is a clear violation of the international law that prohibits extraditing or otherwise transferring persons to a country where they may face torture.
"The Bush administration knows full well that Egypt tortures people in custody, and that its promises not to torture a given suspect are not worth the paper they're written on," Stork said.
"This fig leaf doesn't hide US complicity in the terrible abuses that await suspects sent to Egypt."
Aljazeera.net's requests for an official Egyptian response to the report went unanswered.