The go-ahead for human consumption was delayed until test results on a 20 litre sample were available, and again until a check valve had been fixed.
The water recovery system extracts moisture from the ISS's atmosphere and also turns urine collected in the waste and hygiene compartment into purified water.
"This has been the stuff of science fiction. Everybody's talked about recycling water in a closed loop system, but nobody's ever done it before. Here we are today with the first round of recycled water," said Expedition 19 flight engineer Mike Barratt.
"We're really happy for this day and for the team that put this together. This is the kind of technology that will get us to the moon and further."
Increasing the amount of water available on board the ISS will help support larger crews. Later this month, the normal size of an ISS crew will grow to six.
"This is an important milestone in the development of the space station," said Kirk Shireman, International Space Station deputy program manager at NASA.
"This system will reduce the amount of water we must launch to the station once the shuttle retires and also test out a key technology required for sending humans on long duration missions to the moon and Mars."