Preschool and school-age children are spending most of their time in close touch collectives in which they are exposed to numerous health risks, including possibility of lice disease. Pediculosis is a parasitic infection for which there is a law obligation for reporting the cases to the competent public health authorities in order to be able to monitor it. The main goal of this undergraduate thesis is to show the trend of contagious disease Pediculosis in Primorsko-goranska county in a period of time from 2015. to 2019. year. Results indicate that disease has no continuous growth or decline over years and that the major problem is non-reporting cases of infection in whole country Republic of Croatia. Due to insufficiently precise monitoring, there is no correct insight into the actual picture of the presence of this disease and therefore prevention measures can’t be implemented to extent that the actual incidence of the disease could be known. One of the preventive measures is complete and permanent education of people who work with this population as well as parents of the children as patients