Loneliness is a process that always exists and will exist in the future for all human beings. In addition to life experiences such as death and separation, every individual meets with loneliness within the course of life. A lot of factors cause loneliness. In the context of this study, 434 students who study at High School were interviewed and a questionnaire was applied. UCLA Loneliness Scale was used as the data collecting tool. In the study, loneliness of students is revealed concerning socio-demographical characteristics, social support and school social work. If necessary to summarize basic findings of the research; as to gender, males are more lonely than girls; as to education level of mother, students who have university graduated mothers have less level of loneliness than others; as to education level of father, students who have university graduated fathers have less level of loneliness than others; as to number of siblings, the more number of siblings the more state of loneliness, the more income the more state of loneliness, students who fail in a class feel more loneliness than others. Besides as living a long time in urban places, students who have been living a long time in urban places have less level of loneliness than others.