AVA- Nikos Karakoukis, head of the Athens coroner service, said 86 autopsies had been performed.
Greek Health Ministry said in a statement that a 62-year-old man, who was receiving treatment at Athens' Evangelismos hospital, succumbed to his injuries.
According to the ministry, a total of 51 people are receiving treatment at the hospital, of which four are children. Ten injured people are in critical condition.
On Monday, fires broke out on the east and west coasts of Greece's Attica region, which includes capital Athens, killing 87 people and injuring more than 170.
The fires have forced thousands of locals to flee to safer areas.