Additional District and Sessions Judge Md Abu Taher passed the verdict on Tuesday.
The convicts who received death penalty are Alamin, Mizanur Rahman, Nazmul and Swapan Mia. All of them were present in the court to hear the verdict.
The court also fined the convicts Tk 100,000 each.
On Aug 2012, Kobad Mia and Zakarul were hacked to death with sharp weapons in Karimganj Upazila's Dehunda village.
The killings stemmed from a feud over the theft of a mobile phone owned by Kobad Mia's nephew, said Public Prosecutor Shah Azizul Haque citing the case.
Kobad and Zakarul severely wounded by sharp weapons during the feud died in hospital.
Later, Kobad Mia's wife Sujata Akter started a murder case accusing 27 people. After the investigation, police submitted charges against 25 people.