Introduction: Marfan’s syndrome is a heritable multisystem connective tissue disorder resulting from mutations in the gene for fibrillin-1 (FBN1). This disorder shows a high degree of clinical variability both between and within families. Affected patients are at risk for severe skeletal, cardiovascular and ocular problems. The diagnosis is usually based on clinical features. Material and method: We reviewed the clinical and molecular data of 8 patients who was hospitalised in Paediatric Cardiology Department in Katowice. There were 5 boys and 3 girls, 9-17 years old, referred for FBN1 analysis because they fulfilled the diagnostic criteria for Marfan’s syndrome. The clinical diagnosis and the family history was made by the criteria of the Ghent nosology. Mutation analysis of the FBN1 gene were identified by DHPLC screening of all 65 exons and adjacent intron sequences, followed by direct sequencing of aberrant fragments. Results: All of the patients presented typical clinical manifestation of Marfan’s syndrome. There was no child with the neonatal Marfan's syndrome. Four of them, including 3 persons who were siblings, had a positive family history. Pathogenic mutations were found in the 4 patients and probably pathogenic mutations in the 4 patients too. Conclusions: The clinical diagnosis using the Ghent nosology corresponds to the molecular analysis. Specific genetic tests are difficult of access and expensive so they are not necessary in patients who fulfilling the diagnostic criteria for Marfan’s syndrome.