The big cat pounced on Mohammad Ramzan Dar when he had ventured out of his home this morning, police said.
Dar was rescued by his family members and neighbours, who took him to a nearby hospital. His condition is stated to be critical.
The leopard managed to flee into the nearby forest, police said.
Attacks by wild animals on human beings have increased across Kashmir Valley over the past couple of months, leaving nearly six persons, including three children, dead.
Several black bears and wild cats have also been killed by local residents and the wildlife department.
Earlier on May 24, Forest Minister Mian Altaf had said the government is planning to introduce a low-cost methodology using organic fencing to check increasing number of man-animal conflicts in the state.