Congenital malformations have always been one of major medical and social problems. In epidemiological studies they emerge as one of the main causes of infant mortality. The aim of the study was to analyze the mortality of infants born and deceased in Poznań in years 1998-2001. The main source of information were death certificates which contained the following information: immediate and underlying cause of death, date of birth and date of death, address, birth weight, gestational week. In the analyzed period 50 infants died from congenital malformations. Circulatory system defects, CNS defects and multiple malformations were the most frequent causes of death. The low birth weight children prevailed among those who died from congenital malformations.