Habibur Rahman used to trade in rod and cement in his hometown of Bajgram in Sylhet right after the Liberation War, The Daily Star newspaper said in the report on Saturday.
After he left home at te age of 30, his family members searched far and wide, and did everything they could to track him, but were unsuccessful in finding him.
On Friday, the wife of Habibur's eldest son, who lives in the US, stumbled upon a video post of a man seeking financial help for a patient, who could not be treated for a lack of money.
She had heard stories of her father-in-law's disappearance. She grew suspicious and shared the video with her husband.
Habibur's eldest son immediately called his brothers in Sylhet to go check out the patient.
On Saturday morning, the brothers visited the hospital and confirmed that the patient in the video was none other than their father.
"I remember that my mother and uncles did everything to find him for years, before finally giving up. Later, my mother passed away in 2000," The Daily Star quoted one of the brothers as saying.
For the last 25 years, Habibur had been living at Rayossri area in Moulvibazar, where a woman named Razia Begum used to look after him.
Razia said her family members found Habibur in a disoriented state at Hazrat Shahab Uddin shrine in 1995. "He said he used to live a nomadic life. He has been staying with us ever since. We respect him and call him Peer."
After the reunion, the family took Habibur to a private hospital for better treatment.
( With inputs from IANS )