The aim of the paper is the analysis of the key etiological and phenomenological characteristics of homelessness. Homelessness is a growing contemporary social problem, and its comprehension varies between different societies. The existence of various homelessness definitions has caused forming different typologies. Analyzed socially-demographical characteristics have shown that homelessness affects many people, regardless of gender and age, and is caused by various life events. Homelessness is accompanied by a particular lifestyle and value system that contains elements of subculture. As the most severe case of poorness and social exclusion, homelessness represents a rich ground for development of the various types of behavioral disorders....