By tradition, a wooden cross is cast into the water and it is believed that the person who retrieves it will be freed from evil spirits.
In the central Bulgarian city of Kalofer, 350 men in traditional dress waded into the icy Tundzha River with national flags. Led by the town's mayor and encouraged by a folk orchestra and homemade plum brandy, they danced and stomped in the rocky riverbed.
In the Romanian Black Sea port of Constanta, some 3,000 Orthodox believers turned out to watch priests hurl three crosses into the icy sea. Dozens some wearing diving suits dived into the waters to retrieve the crosses.
"We the people are so like the sea," said Romanian Orthodox Archbishop Teodosie Tomitanul. "We hope that, as the sea has been calm until now this year, our souls will be just as calm."
Some Orthodox Christian churches, including those in Russia, Egypt, Syria and Lebanon, follow a different calendar, and Sunday was Christmas Eve, with Epiphany on Jan. 19.