The Duke of Edinburgh told a nurse her country must be "half empty" because so many Filipinos work for the NHS, during a tour of hospital yesterday.
Prince Philip, who is well-known for his off-the-cuff remarks - that have occasionally caused controversy, joked about the number of Filipinos working in the NHS.
The 91-year-old made the comment during a visit to open a £5.5 million cardiac centre at Luton and Dunstable Hospital.
He was heard telling the nurse: "The Philippines must be half-empty - you're all here running the NHS."
During the visit the Prince described his mood as "jovial" and also joked he was the "world's most experienced curtain puller" and asked when the hospital would be getting a helipad to save him by the journey by car.
The Duke's most famous remark came during a 1986 state visit to China when he told British students: "If you stay here much longer, you'll all be slitty-eyed."
Prince Philip also once told a group of deaf youngsters "Deaf? If you are near there, no wonder you are deaf," referring to a school's steel band.
In 1995 he asked a Scottish driving instructor: "How do you keep the natives off the booze long enough to pass the test?"
In keeping with tradition Buckingham Palace yesterday refused to comment on the latest remarks from the Prince saying: "We do not comment on private conversations."
The hospital spokesman said of the visit: "Staff greatly enjoyed the opportunity to meet the Duke of Edinburgh, and we regard all personal conversations he had with our staff and guests as private and therefore would not comment on them.
"Luton is a very cosmopolitan town and the working staff at Luton and Dunstable hospital reflects that."
Ten of Philip's most famous gaffes from the Independent's:
1. "Ghastly." Prince Philip's opinion of Beijing, during a 1986 tour of China.
2. "Ghastly." Prince Philip's opinion of Stoke-on-Trent, as offered to the city's Labour MP Joan Walley at Buckingham Palace in 1997.
3. "Deaf? If you're near there, no wonder you are deaf." Said to a group of deaf children standing near a Caribbean steel drum band in 2000.
4. "If you stay here much longer, you will go home with slitty eyes." To 21-year-old British student Simon Kerby during a visit to China in 1986.
5. "You managed not to get eaten then?" To a British student who had trekked in Papua New Guinea, during an official visit in 1998.
6. "You can't have been here that long – you haven't got a pot belly." To a British tourist during a tour of Budapest in Hungary. 1993.
7. "How do you keep the natives off the booze long enough to pass the test?" Asked of a Scottish driving instructor in 1995.
8. "Damn fool question!" To BBC journalist Caroline Wyatt at a banquet at the Elysée Palace after she asked Queen Elizabeth if she was enjoying her stay in Paris in 2006.
9. "It looks as though it was put in by an Indian." The Prince's verdict of a fuse box during a tour of a Scottish factory in August 1999. He later clarified his comment: "I meant to say cowboys. "I just got my cowboys and Indians mixed up."
10. "People usually say that after a fire it is water damage that is the worst. We are still drying out Windsor Castle." To survivors of the Lockerbie bombings in 1993.