Integration of oral healthcare into primary care is recommended to improve the oral health of patients. This study assessed oral health knowledge among family physicians in Malaysia. A postal survey was done on family physicians working at the Ministry of Health primary healthcare facilities. Structured questionnaires containing 85 items assessing 5 sub-domains were delivered to 350 family physicians. A total of 138 responses were analysed. Most family physicians were able to identify the risk factors as well as signs and symptoms of dental caries, periodontal disease, and oral cancer, and recognize the link between oral diseases and general health, the oral side effects of medications, and the correct oral hygiene practices. However, misunderstandings were also common such as not knowing that dental caries is an infectious disease (56.5%) and a poorly fitting denture is a risk of oral cancer (60.1%) and having the misconception that the developing foetus draws calcium from the mothers’ teeth (60.0%). The mean knowledge score was significantly higher in physicians who had attended an in-service training program on oral health than those who had not. In conclusion, most family physicians in this study had adequate basic knowledge about oral health although some common misunderstandings in several issues. A significant relationship was found between oral health knowledge and experience of attending in-service oral health education programs. A structured continuous professional development program to improve oral health knowledge of family physicians and other primary healthcare providers is recommended.