He had just returned from Ethiopia where he took over the rotating chairmanship of the African Union.
Africa’s oldest leader, who turns 91 later this month, had concluded his homecoming speech when he tumbled to his knees on a short flight of stairs in an incident witnessed by journalists and hundreds of supporters.
He was quickly helped up by aides and walked to a waiting car.
Mugabe took over the post of African Union chairman on Friday, replacing Mauritania’s President Mohamed Ould Abdel Aziz.
The former liberation war hero is Africa’s third-longest serving leader.