Admission of young adult in Intensive Care Unit (ICU) consists a complex phenomenon with various dimensions. The aim of the present study was to explore the causes of admission in Intensive Care Unit of young adult 18-30 years old according to their demographic variables. Method and material: The sample of the present study consisted of individuals’ age 18-30 years old that were hospitalized in Intensive Care Unit during 2005-07. Data was collected by the use of a specially designed clinical protocol which besides the demographic data included variables related to the causes of admission, the duration of treatment as well as the outcome of the disease. For the analysis of data the statistical packet SPSS v.13 was used and the method x2. Results: 74,9% of the sample studied was men and the 25,1% women. Regarding nationality, 78,4% were Greek whereas 21,6% were foreigners. The fist reason of admission in ICU was road accidents with percentage 59,4%, pathological problems followed with 14,1%, the post-operative period with 9,8%, work accidents with 5%, criminal actions with 4,2%, suicide attempt with 4% and the use of drugs with 3,5%. The statistical analysis of data showed that : regarding the relation of admission to marital status and occupation, students, private employees and free-lancers who were not married were more likely to be involved in road accident, p<0,001. The foreigners were admitted more frequently because of work accidents and criminal actions with statistical significant difference compared to Greeks, p<0,001, respectively. On the contrary, Greeks admitted less frequently because of suicide and pathological problems with statistical significant difference compared to foreigners, p<0,001, respectively. Conclusions: Social and demographic variables significantly affect admission of young in Intensive Care Unit.