Abramovic was struck on the head with a wood-framed canvas on Sunday in the courtyard of Palazzo Strozzi.
The painting is a portrait of Abramovic and was reportedly painted by the attacker himself.
The museum is currently hosting a retrospective about Abramovic, which will run until January 20, 2019.
The palazzo’s director, Arturo Galansino, took to Twitter to confirm that the artist was uninjured after the bizarre attack, which many witnesses initially believed to be part of a performance.
Local police are currently investigating the incident.
Italian media have reported that the attacker is a 51-year-old artist from the Tuscan capital who has twice been naked in public in recent years.
