A big part of traditional architecture both in rural and urban areas in the Greek territory has been built with raw earth. The aim of this paper is to present earthen buildings’ constructions in Greece and show their important contribution to our heritage. The use of earth as a basic constructing material has given different earthen building cultures and techniques. Earthen construction encloses many varied uses and applications, as walls or as plasters. In different periods of time and historical contexts, from the indigenous inhabitants to the neighborhoods of the refugees of Asia Minor Catastrophe, the earth constructions had a primary role. The existence of earthen architecture was investigated in urban and rural sites in Greece. Building information, documentation, and records of buildings’ design, construction techniques, elements, and systems are presented. Today, there is still a rich architectural heritage throughout the country, which has lasted through the years and withstood seismic activities and poor conservation.