Primary health care workers (HCWs) provide almost all vaccine services in Croatia, so they play an essential role in vaccine recommendations and uptake. The aim of this study was to determine the level of vaccine hesitancy among primary HCWs, to identify differences between nurses and physicians in attitudes, beliefs and behaviours towards vaccination, and to determine predictors of vaccine hesitancy among HCWs. We conducted a cross-sectional study from July to December in 2018 among physicians and nurses employed in the services of epidemiology, public health, school medicine, pediatrics and general practice/family medicine in Primorje-Gorski Kotar County, a primarily urban region with a population around 300 000 in the northern part of Croatia. The list of primary HCWs offices was obtained from the Croatian Health Insurance Fond website. We used a self-administered questionnaire on their attitudes, beliefs and behaviours relative to vaccination. Obtained response rate was 65.5% (324/495) of eligible primary HCWs; 64.1% (143/223) of physicians and 66.5% (181/272) of nurses. Seventeen percent of HCWs were identified as vaccine hesitant, and in univariate analysis, we observed an association between HCWs occupation and their own vaccination against flu (p = 0.001), measles (p = 0.016) and HPV (p = 0.025). Nurses and physicians differed (p < 0.001) in their general attitude, beliefs and behaviours towards vaccination, with a higher level of hesitancy among nurses. In multiple logistic regression, those more likely to be vaccine-hesitant were nurses (AOR = 5.73, 95%CI = 2.48-13.24), those who were uncertain or would never receive a vaccine against measles (AOR=11.13; 95%CI=5.37-23.10) and HPV (AOR=5.02; 95%CI=2.60-9.74), as well as those who had encountered a serious adverse event following immunization (AOR=7.55; 95%CI=3.13-19.18). As personal hesitancy may have a negative impact on vaccination education and recommendations, and therefore vaccine coverage, it is necessary to implement interventions to increase vaccination knowledge and confidence among primary health care workers, especially nurses.