Legendary poet Al Mahmud died while undergoing treatment at Ibn Sina Hospital at Dhanmondi in the capital on Friday night.
He breathed his last at 11am, his family friend Abid Azim confirmed the death in a facebook post.
Earlier on 9 February, Al Mahmud admitted to the Intensive Care Unit of Ibn Sina Hospital as he fell sick.
Mahmud was born on born on 11 July, 1936. He is considered one of the greatest Bengali poets to have emerged in the 20th century.
His work in Bengali poetry is dominated by his frequent use of regional dialects.
In the 1950s he was among those Bengali poets who were outspoken in their writing on such subjects as the events of the Bengali Language Movement, nationalism, political and economic repression, and the struggle against the West Pakistani government.
Mahmud started his career as a journalist. He obtained widespread recognition after Lok Lokantor was published in 1963.
In succession, he wrote Kaler Kalosh (1966), Sonali Kabin (1966) and Mayabi Porda Dule Otho (1976).
His other notable poetical works include, Arobbo Rojonir Rajhash, Bakhtiyarer Ghora and Nodir Bhitorer Nodi.
In addition to writing poetry, he had written short stories, novels and essays such as Pankourir Rakta and Upamohadesh. He took part in the Liberation War of Bangladesh as a freedom fighter in 1971.