Illness and hospitalization are conditions leading to negative effects in children's lives regardless of their age. This study was performed descriptively in order to examine the fears of hospitalized children for illness and hospital. The study was descriptive and sectional and performed in Karabuk University (Turkey) Training and Research Hospital between February 1 and May 1, 2015. Sample of the study was composed of 144 children who were hospitalized due to an acute illness and their parents who approved to participate in the study. Participant information form and an information form that was prepared to evaluate the fears of children for illness and hospital were used as data collection tools. Data were collected by face-to-face interview technique. Statistical analyses were used to assess data. It was found that 56.2% of children in the study were males and were between 7 and 10years of age; 42.4% were scared of getting illness. 39.5% of 86 children who were previously hospitalized have stated that they experienced fear due to hospitalization; injections were in the first place among causes of fear by 64.7%. When the causes of children's fear for illness and hospital were examined, it was determined that undergoing an operation (3.21 +/- 1.13), staying away from the family during hospitalization (3.11 +/- 0.96) and worrying the family when he/she gets an illness (3.02 +/- 1.05) were in the first three ones. When the relationship between some characteristics of the children and their parents and children's status of fear for illness was investigated, it was detected that there was a significant difference between their previous fear of hospitalization and their current status of fear for getting illness (p=0.003). It was observed that children in the study experienced fear for illness and hospitalization and the percentage of children with fears was found to be high. It was also determined that undergoing an operation, staying away from the family during hospitalization and worrying the family when he/she gets an illness were among the first causes of their fears.