BackgroundThe number of migrants to Greece has increased considerably the last decade. This study assessed the knowledge and attitudes of healthcare personnel (HCP) toward vaccination of newly-arrived children and adolescents in the Aegean islands, a major port of entry of migrants and refugees to Europe. MethodsThe study was conducted from September 2020 to January 2021. All (166) HCP employed in the public health sector of the Aegean islands were invited to participate. A structured questionnaire was used to collect demographic data and data about their knowledge and attitudes toward vaccinations for migrant and refugees. ResultsA total of 120 HCP participated (72 % response rate), including 54 (45 %) physicians, 43 nurses (35.8 %), and 23 health visitors (19.2 %). Sixty-seven (55.8 %) HCP were aware of the national vaccination guidelines. Health visitors had higher rates of knowledge about the national vaccination guidelines, compared with nurses and physicians (87% versus 44,2% and 51,9%; p-value-0.001). Overall, 73 (60.8 %) HCP were aware of vaccinations during the first examination upon arrival. Primary-healthcare physicians were more likely to be aware about the time of vaccine administration compared with hospital-based physicians (74 % versus 50 %; p-value = 0.006). Out of 120 HCP, 45 % knew that vaccination guidelines apply to all newly-arrived migrant and refugees and 65 % that vaccinations are free-of-charge. Overall, 67.5 % of participants supported no serology testing before vaccination, 21.8 % were against free-of-charge vaccinations, and 55 % recommended only priority vaccinations. ConclusionsThere is a need to increase HCP’ awareness and knowledge through training programs and tailored protocols focusing on vaccinations for newly-arrived migrant and refugee children and adolescents in order to promote effective vaccination of this vulnerable population.