Introduction: To maintain high vaccination rates, vaccination interventions should be targeted according to interests such as parents' knowledge, attitudes, beliefs, and vaccine hesitancy.Methods: This research was conducted between June 2020 and April 2021 using a questionnaire about optional vaccines (OVs) in Turkey.Results: A total of 241 physicians participated and 14 physicians were excluded due to insufficient data. Finally, a total of 227 physicians, including 115 pediatricians and 112 family physicians, were included in the study. The mean age of pediatricians and family physicians was 33.42 ± 8.25 years and 35.46 ± 11.09 years, respectively. There was no significant difference between pediatricians and family physicians in terms of age and gender (p > 0.05). Nearly half of all physicians (49%) stated that they do not have sufficient knowledge about OVs. Pediatricians (64%) stated that they have sufficient knowledge at a higher rate than family physicians (37%) (p = 0.000). Physicians who declared having sufficient knowledge informed families about OVs more frequently than those with insufficient knowledge (p = 0.000). Pediatricians provide information about OVs more frequently than family physicians (p = 0.001). Rotavirus and meningococcal vaccines were the most frequently recommended vaccines.Conclusions: Rotavirus and meningococcal B were the most recommended OVs. About half of the physicians participating in the study stated that they did not have sufficient knowledge about OVs. Physicians with sufficient knowledge of OVs recommend OVs more frequently.