Ironically, the sentencing came on a day when Pakistan was celebrating its second Oscar win when filmmaker Sharmeen Obaid Chinoy's documentary on honour killings in the country won the prestigious award in Los Angles.
A sessions court's here sentenced to death Ahsan and Zeeshan Butt who had shot dead their sister, Saba, and her husband, Shafiq, for marrying out of their own will.
Judge Naveed Iqbal also imposed a fine of Rs one million each on the convicted men.
More than 500 men and women died in honour killings in 2015, according to the Human Rights Commission of Pakistan.
Honour-killing is a big issue in Pakistan and every year dozens of women are killed.
Prime Minister Nawaz Sharif said last week that there was no honour in honour-killing and promised to take measure to wipeout the practice.