Abstract Cysitic fibrosis (CF) is one of the most common autosomal recessive diseases. The median life expectancy is currently about 30 years. Because of a considerable social meaning of CF, it is very important to create more specific and efficient methods diagnosing defects in the gene CFTR that are responsible for CF. The use of these methods in preimplantation diagnosis could prevent the disease and also the carrier state. Objectives: The aim of this study was to construct a diagnostic test for five CFTR gene mutations, the most frequent in Polish population, which can be used to analyze single cells while preimplantation genetic diagnosis. Material: The material used in research were 60 single cells – blastomers. The positive controls of the CFTR gene mutations : delF508, R117H, G542X, R553X, dele2,3 were obtained from blood of patients with CF. At first Nested Multiplex PCR reaction was performed. Its products were used as DNA template for the next reaction - ASA (allelespecific amplification) PCR. SSCP method (Single Strand Conformation Polymorphism) was used as a verification method. Results: The diagnostic test for the presence of the mutations: delF508, R117H, G542X, R553X and dele2,3 (when homozygosity) was constructed. Mutations: delF508 (3 cells – 5%), G542X (2 cells – 3,33%) and R553X (1 cell – 1,67%) were detected as a result of performing ASA PCR analysis for the presence of the CFTR gene mutations in 60 blastomers. The SSCP analysis for the mutations delF508, R117H, G542X, R553X confirmed the results of ASA PCR analysis. Conclusions: The constructed diagnostic test for the mutations delF508, G542X, R553X, R117H and dele2,3 can be used to analyze single cells during preimplantation genetic diagnosis.