The chief justice of the United States has been released from hospital after suffering a seizure.
Mr Roberts is said to have had a previous seizure in 1993
John Roberts, 52, collapsed at his holiday seaside home in the north-eastern state of Maine on Monday.
The father-of-two underwent a "thorough neurological evaluation, which revealed no cause for concern", a spokeswoman for the Supreme Court said.
The White House said Mr Roberts had telephoned President George W Bush and had sounded "in great spirits".
Chief Justice Roberts is a conservative appointed by President George W Bush in 2005.
He succeeded William Rehnquist, who died of cancer.
Mr Roberts has helped position the Supreme Court - which began its summer recess last month - on the political right over issues like abortion, race in schools and Guantanamo Bay.
He had had a previous seizure in 1993, according to the spokeswoman. The Associated Press said Mr Roberts had made the president aware of this when he was appointed.
The senior judge fell ill at a dock near his summer home on Maine's Hupper Island.
Mr Roberts was taken by ambulance to the Penobscot Bay Medical Centre after his fall, where he was kept overnight.