The visas are valid for Pakistani citizens who are above the age of 65.
"We have launched visa on arrival facility to Pakistani senior citizens at the Attari Integrated Check Post from April 1," a Home Ministry official said.
However, no decision has been taken on the stalled group tourist visa facility to Pakistani nationals. The two countries had agreed to operationalise the group tourist visa facility to be offered to each other's citizens from March 15.
The reason for the sudden launch of the visa for Pakistani senior citizens was not immediately known.
Prime Minister Manmohan Singh had last month said that the barbaric killing of Indian soldiers in Kashmir had cast a shadow on bilateral relations and asked Pakistan to create a conducive environment to take the normalisation process forward.
Dr Singh had earlier said that it cannot be "business as usual" between the neighbours following the LoC incident.
The new visa agreement was signed last September to ease cross-border travel as part of a number of Confidence Building Measures (CBMs).
Some clauses of the relaxed visa regime like multiple-entry and reporting-free visas for businessmen and allowing them to travel to five cities instead of the earlier three were operationalised when Pakistan's Interior Minister Rehman Malik visited New Delhi in December.