AIM: To analyse preterm infants who have developed the infection and determine the impact of gestational age, birth weight, Apgar score, gender of the child, age, education and parity of mothers on the development of infection in children and the impact of infection on the complexity of nursing care. Show the types of infections by organ systems. SUBJECTʼS AND METHODS: The medical records of premature infants treated at the Department of Neonatology of the Clinical Hospital Center Split, born from 1 January 2016 to 31 December 2018, were retrospectively reviewed. The study looked at 351 premature babies who developed the infection and their mothers. Data about birth weight, gestational age, Apgar score, gender of the child and mother´s age, parity and education were taken into account. RESULTS: Out of a total of 821 premature infants born during the three – year period, there were 351 (42,3%) preterm infants who developed the infection. There was a significant difference in preterm infants of lower birth weight and lower gestational age who developed the infection compared to preterm infants of higher birth weight and gestational age (p<0.001). The gender of the child and the age of the mother have no influence on the development of infection in children. 51.6% of children who have developed an infection have an Apgar score between 8 and 10. The biggest number of preterm infants have developed a respiratory infection, 24.5% of them. Children of first-born mothers are more likely to develop the infection. The analysis of the data established that in 68.1% of cases mothers of the children who developed the infection completed secondary education and in 31,9% of cases they had higher or high expertise. Nursing care in preterm infants who have developed an infection is a more complex and requires more specific nursing procedures. CONCLUSIONS: Lower gestational age and lower birth weight significantly affect the development of infections in preterm infants. Research has shown that first – borns have a greater impact on the development of infection in children. The gender of the child and the age of the mother did not show a statistically significant effect on the development of infections in children. Nursing care in preterm infants who have developed an infection is a more complex and requires nurses with knowledge and exceptional skills.