The paper presents the results of taxonomical investigation of the genus Cladonia Hill ex P. Browne from King George Island . Individuals belonging to this lichen genus were studied using methods of classical herbarium taxonomy supported by chemical analysis. Fourteen species have been recognized in the study area, with C. asahinae J.W. Thomson being reported from King George Island for the first time, and C. cervicornis subsp. mawsonii reported as new for the South Shetland Islands. The occurrence of C. cariosa is confirmed for the Antarctic region. The diagnostic characters, ecology and important remarks referring to particular species are briefly presented. An updated key for identification of the species from King George Island and neighbouring islands of South Shetlands is included.