Cystic fibrosis is a hereditary disease that causes the respiratory and gastrointestinal system symptoms. It is caused by genetic mutation and it can be diagnosed by sweat test or by detecting cystic fibrosis mutations in patients with characteristic symptoms. Cystic fibrosis is treated symptomatically because there is no known cure for this genetic disorder and because of that treatment lasts for a lifetime. Nursing care of children diagnosed with cystic fibrosis begins in early childhood, and then lasts throughout life and all phases of growing up, including the terminal phase. A nurse who works with such complex patients should have specific education, adequate approach to the child and parents and be expert. This paper presents the knowledge of the general population about cystic fibrosis that was tested by five hypotheses. With this hypothesis it was investigated the knowledge of people of different sex, age, lower and higher expertise, socio-economic status, and the kowledge of people who know or do not know the person with cystic fibrosis.