The Russian Orthodox Church counts in its congregation more than 100 million people in Russia and tens of millions elsewhere. But polls show that only about 5 percent of Russians are observant believers.
State television broadcast much of Tuesday's session live. In opening remarks, Kirill thanked President Dmitry Medvedev's administration for "warm and very benevolent greetings."
Both Putin and Medvedev called Kirill later to congratulate him.
Associated Press Writers Nataliya Vasilyeva, Jim Heintz and Steve Gutterman contributed to this report.