We investigated awareness in dental hygienists of bisphosphonate-related osteonecrosis of the jaw (BRONJ) in patients with osteoporosis and cancer and assessed the situation in systemic history investigations to broaden the scope of the dental hygienists’ BRONJ awareness as a basis for contributing to preventing this disease. The study was carried out through a survey; 217 dental hygienists responded to the survey. They worked at 12 university and general hospitals, 10 dental hospitals and 35 dental clinics, for a total of 57 institutions in Seoul. The survey consisted of 37 questions: general characteristics (J Oral Maxillofac Surg 65: 2007; 369), systemic history investigations (Ruggiero et al. J Oral Maxillofac Surg 62: 2004; 527) and awareness of BRONJ (Park et al. J Korean Dent Assoc 49: 2011; 389). Among them, 79.7% were aware of BRONJ. Recognition was highest among those from 25 to 35 years old (P < 0.05). In terms of work experience, those with 5–10 years experience showed the highest awareness (P < 0.05). In terms of institutions type, dental clinics showed lower awareness than general and dental hospitals (P < 0.05). It was found that 55.3% of the dental hygienists had been educated about BRONJ. Those aged 25–35 years were the most educated. In terms of institutions, dental clinic staff were the least educated. The degree of understanding about BRONJ was analysed with the average score of 6.14 points. According to these results, dental hygienists working in university hospitals and general hospitals had more opportunity to receive training than those working in dental clinics. Thus, it is considered that the development of professional training programs about BRONJ for all dental hygienists is necessary.