OBJECTIVES: The aim of our research was to reveal risk factors for developing infections. We assumed that children younger than two years will be more likely to develop infection. We also thought that duration of a specific invasive procedure will be associated with the development of infection. DESIGN: The historical prospective study. The study included all hospitalized in JILD-in, in the period from january to december 2010. We investigated the risk factors that contribute to the development of infection. SETTINGS: The study was conducted in the Intensive care unit, Department of pediatrics, at Clinical hospital centre Split. PARTICIPANTS: The study included 196 patients, of which 120 male and 76 female, hospitalized in the intensive care unit. They were divided into two groups: those who developed and those who did not develop infection. MAIN OUTCOME MEASURES: The main outcome measure was confirmed infections of the respiratory and urinary systems and the development of sepsis caused by methicillin-resistant bacteria: Staphylococcus epidermidis and Staphylococcus aures and bacteria: Escherichia coli and Klebsiella pneumoniae during treatment. RESULTS: Under biggest risk were infants (0-28 days) (χ2 test = 27.324, df = 4, P <0.001). We didn’t prove association of sex with the development of infection. The most important risk factor for the development of infection was the umbilical catheter (χ2 test = 31.1, df = 1, P <0.001). The most common infection was blood infection. The duration of mechanical ventilation (Z = -4.198, P <0.001 and intravenous catheters (t = - 3.82, P <0.001) was proved to be significant in the development of infection, but the duration of urinary catheter was not. CONCLUSIONS: The study showed that using a variety of invasive procedures in the intensive care unit is associated with the development of infection. Also, the duration of a particular procedure is important for infection. Gender is not important in the onset of infection. Group at risk of infection are children younger than one year. In that group the most frequent was used umbilical catheter what connects it as a risk factor for the bloodstream infections.