Introduction: During the last two centuries, there is a significant trend in the increase of accessible vaccines for prevention of infections diseases. In that time vaccines quality is constantly improving. But even in the highly developed countries, with previously high immunization rate there is a remarkalble increase in vaccination hesitancy resulting in an incresaed proportion of parents who refuse vaccination of their children. ----- Aim Aim of the study is to assess attitudes of mothers toward immunization of preschool children. The hypothesis says that mothers attitudes affect the vaccination of their children. -----Materials and methods: Dan Kahan, Yale Law School Harvard University - Edmond J. Safra Center for Ethics questionnaire was adapted. The questionnaire consists of three parts: the first part about socio – economic data, the second part consists of immunization data for all children and the third part about consists of attitudes about immunization. The sample included healthy mothers who were at regular check up at the Gynecological-Outpatient Clinic for gynecology and obstetrics at the Mostar University Clinical Hospital and who had at least one child up to 7 years. 200 mothers were included out of them 163 (81,5%) properly filled the questionnaire. Results: The results didn’t confirm a connection between age, school education, and mothers' employment status and attitudes towards vaccination. By factoral analysis, three factors were extracted. Percentage of explained variance in the principal component analysis range from 40% to 72%. The first one, positive factor, is described by 7, the second, negative factor, by 4 and the third, hesitancy factor, by 3 items. ----- Conclusion: The research results show that the children of our respondents had a higher vaccine coverage compared to the official data provided by the Federation of Bosnia and Herzegovina Public Health Institute. Coverage by recommended vaccination decreases with the age of the child. Mothers have attitudes that are positive for vaccination, negative and hesitant and these attitudes are not mutually exclusive.