The first cases of influenza appeared in Czechoslovakia around Christmas and the peak was reached about January 20. The epidemic came from the southwest, as in 1918, while the epidemic of 1889 came from the east. The meeting of the Association of Czech Physicians, January 17, was devoted to the discussion of the present epidemic. Although the cases are mild, nevertheless, in 1918 the first wave, which appeared in the spring, was mild, while the second wave, which came in the summer and early fall, caused dreadful mortality. Clinically, the disease causes either a general reaction accompanied by fever, or catarrhal symptoms which are limited to the upper air passages. The minority of cases present signs of diffuse bronchitis with an inclination to bronchopneumonia. Generalized pain, pain in the back, and bleeding from the nose are common. Serious injury to the heart is seen only in very old patients.