The article is devoted to the analysis of the public opinion of the Russia during the Schleswig-Holstein crisis of 1863-1864. The Schleswig-Holstein question is considered one of the most difficult international relations in history, not only because it was part of the unification of Germany, but also because it was a part of the struggle of the European powers for economic and strategic leadership in the Baltic region. How and why were these events perceived by Russian society? The traditional source of public opinion research was the press. The greatest contribution to informing and discussing events in Denmark was made by such newspapers as Vest', Den', Golos, Moskovskie Vedomosti and other leading russian newspapers. The first part of article is devoted to the internal state of Russia by 1863-1864, including the conditions for existing of public opinion. Russian periodicals not only provided operational information, but also formed a definite view of events in Denmark. The second chapter is devoted to reflection of periodicals on the main events of the Schleswig-Holstein crisis of 1863-1864: the escalation of the Schleswig-Holstein issue in 1863, the beginning of the Austro-Prussian-Danish war in February 1864, the diplomatic efforts of neutral powers to stop the war, the policy of European states.