Several women are murdered by relatives in the country each year on the pretext of defending what is seen as family honour, but it is rare for victim to be a man.
The murder happened at a marketplace in the Punjab city of Burewala on Friday, when Muhammad Irshad, 43, was attacked by his father-in-law and two brothers-in-law, police said.
“The assailants were armed with knives and hatchets and after inflicting several wounds on Irshad’s body they slit his throat,” district police chief Ghazi Salahuddin told AFP.
Irshad had married Mussarat Bibi, the daughter of a rich local agricultural family, about a year ago and fled as he feared his in-laws would kill him, but he had returned to see his parents, the police chief said.
A manhunt had been launched to find Irshad’s in-laws, who remained at large, he added.
Last week 16 year-old Zeenat Bibi was killed in Lahore by her mother for marrying a man of her own choice in a case that sparked condemnation throughout the country.
It was swiftly followed by another killing, of a couple in Lahore who married without their family’s consent.
On Thursday relatives slit the throat of a young mother who was pregnant with her second child after she married against their will in the village of Buttaranwali, some 75 kilometres (46 miles) north of Punjab provincial capital Lahore.
On Sunday a young girl was killed by her brother for insisting on marrying the man of her choice in the city of Sialkot, also in Punjab.
A film on honour killings in Pakistan won an Oscar for best documentary short in February.
Prime Minister Nawaz Sharif vowed to eradicate the “evil” amid publicity for the film, “A Girl in the River: The Price of Forgiveness”, but as yet no fresh legislation has been tabled.