Ledra Street was opened recently for the first time in decades
Mehmet Ali Talat has become the first Turkish Cypriot leader for decades to walk down Nicosia's Ledra Street into Greek Cypriot territory.
Mr Talat, flanked by security staff, chatted to shopkeepers and bought ice cream, coffee and CDs.
Ledra Street was opened a week ago for the first time since 1964.
Relations between the island's divided communities have thawed since the election of a new Greek Cypriot president in February.
'Message of friendship'
President Demetris Christofias stood on a platform of resuming negotiations with the North and reuniting the island.
The opening of the Ledra Street crossing has been seen as a major confidence-building measure before peace talks resume in June.
"My visit to Ledra sends a message of friendship and Turkish Cypriot efforts to solve the Cyprus problem," Mr Talat told reporters.
"I have come to see what is going on here to experience the new climate," he added.
The Turkish Cypriot leader said he had walked down the street on the spur of the moment.
Ledra Street is the sixth crossing point to open on the island in recent years, but it was seen as one of the most symbolic of the enduring divisions.
The street was closed after violence flared between the Greek and Turkish Cypriot communities in 1964.
Cyprus has been divided since 1974 when Turkish troops invaded the North in response to a coup backed by Greece.
A United Nations-patrolled buffer zone marks the division of the island.