Sawan Masih was sentenced by Additional District and Sessions Judge Chaudhry Ghulam Mustafa at the Kot Lakhpath Jail here.
He was convicted of insulting the prophet Muhammad during a conversation with a Muslim friend in the Joseph Colony neighbourhood of Lahore in March last year.
The trial was held in the jail because of security issues. The judge also imposed a fine of Rs 200,000 on Masih.
In March last year, over 150 homes of the minority Christian community were burnt down by a Muslim mob when the incident came to light.
Mere allegations of blasphemy have triggered violence against minorities like Christians.
Several persons accused of committing blasphemy have been lynched in recent years.
Rights groups have said the blasphemy law, which carries the death penalty, is often misused to persecute minorities and to settle personal scores.
