The US State Department has said that Secretary of State Hillary Clinton has been discharged from New York-Presbyterian hospital.
She was admitted for treatment of a blood clot in a vein behind her right ear.
The State Department said her medical team has reported she is making good progress and is confident she will make a full recovery.
Earlier, local media reported that Mrs Clinton had left the hospital accompanied by her family and an aide, but returned around 15 minutes later.
Mrs Clinton's health has drawn intense media scrutiny given that she is widely considered a strong candidate for the Democratic nomination for president should she decide to run in 2016.
She long ago announced her intention to step down as Secretary of State.
President Barack Obama, whose second term starts later this month, has nominated US Senator John Kerry to replace her.
The State Department announced on Sunday that Mr Clinton was in a New York hospital for treatment of a blood clot that stemmed from a concussion she suffered in mid-December.
The concussion was itself the result of an earlier illness, described by the State Department as a stomach virus she had picked up during a trip to Europe that led to dehydration and a fainting spell after she returned to the US.
In a statement released by the State Department on Monday, Mrs Clinton's doctors said they were confident she would make a full recovery and that she would be released from the hospital once the correct dosage of blood thinners had been determined.