Just hours before Blair's arrival on Monday, four small bombs exploded outside branches of the British bank HSBC in Ankara and Istanbul. No one was reported injured.
However, security worries are the least of Blair's concerns as the six-hour visit will provide only brief respite from his domestic woes.
British media are already speculating about his political future because of the worsening situation in Iraq and falling popularity ratings.
Blair is expected to praise Turkey's political reforms and stress its importance as a moderate Muslim country espousing democratic, secular values.
Turkish Prime Minister Tayyip Erdogan, who is due to pay a reciprocal visit to London in late May, is canvassing the support of EU leaders before they take a decision in December on whether Ankara is ready to begin talks to join the bloc.
"The British view is that it has never been more important to stretch out a hand to Turkey, to show there is no basic contradiction between Islam and democracy. There is so much riding on its EU candidacy," said one Ankara-based diplomat.
Blair suffering the worst ratings
in his seven-year rule
Turkish newspapers said Blair would also express support for direct air links between Britain and Turkish Cypriot-held northern Cyprus, which is recognised only by Ankara but is starting to emerge from decades of international isolation.
Iraq, which has badly sapped Blair's support at home, will also feature on Monday's agenda.
As NATO's only Muslim member, Turkey is worried about possible moves towards independence by the Kurds of northern Iraq, who are a key US ally.
Ankara fears this could reignite separatist violence among the Kurds of southeast Turkey.
Some Turkish left-wing groups say they are planning protests against Blair's visit over Iraq.
The four bomb blasts early on Monday morning recalled attacks in Istanbul on a key branch of the bank last November.
More than 60 people died in that attack, including the British consul. It was blamed on Islamist groups opposed, like most Turks, to the war in Iraq.