Publised: 30 September 2013
Dozens were also wounded when a bomb exploded in the Kissa Khwani bazaar, setting shops and vehicles alight.
It was the third deadly blast to hit the city in a week.
Last weekend suicide blasts killed at least 81 at a church in Peshawar and on Friday, 19 people died when a bus carrying civil servants was attacked.
Peshawar, the main city of Khyber Pakhtunkhwa province, has been hit by numerous bomb and gun attacks blamed on Taliban insurgents but it has rarely come under such sustained attack in recent years.
It is unclear how the three attacks are linked. A Sunni militant group with Taliban links claimed the church attack, but no group has said they carried out this latest blast.
Police said they suspected Sunday's explosion was caused by a car bomb.
A huge blast in the heart of the market set off fires that engulfed shops and vehicles.
One shop owner, Nazar Ali, told Associated Press: "It was a huge blast that was followed by fire in vehicles. Thick black smoke covered the air and splinters spread all over. I saw people lying dead and bleeding.
"Among the dead were at least 14 members of the same family who were at the market making preparations for a wedding, reports said.
Rising violence has hindered new Prime Minister Nawaz Sharif's overtures to end the insurgency through peace talks with the Taliban.
On 21 September, Pakistan released from the jail the co-founder of the Afghan Taliban, Mullah Abdul Ghani Baradar.
But the Pakistan Taliban have consistently rejected the country's constitution and demand the imposition of Sharia law.
The city of Peshawar is still reeling from a week of brutal attacks that has left dozens dead
The latest attack, which hit a historic market, killed at least 42 people
Scores were hurt in addition to those killed in the blast
A remote-controlled car bomb was used, officials said
PM Nawaz Sharif said the bombing was an attack on humanity
Mr Sharif strongly condemned the Peshawar bombing. In a message from New York, where he was at the UN, he said: "Those involved in the killing of innocent people are devoid of humanity and all religions.
"Last Sunday's attack on the historic All Saints church - thought to be the deadliest attack against Christians in Pakistan - sparked angry protests nationwide.
Two Islamist militant groups with Taliban links said they had ordered the attack to hit back at US drone strikes.
Friday's bus bomb targeted government employees returning home in the Gulbela area, some 15km (9 miles) north-east of the city.
In addition to those killed, at least 34 people were injured.
Source: BBC News Asia