Communication is an integral component of effective healthcare delivery to patients, and this includes breaking bad news (BBN). However, clinicians in dentistry are rarely exposed to diseases that can negatively and seriously affect an individual's view of their future and pose a mortality risk, except for oral cancer. The aim of this study was to assess clinician practices in BBN of oral cancer diagnosis in Malaysia. An exploratory sequential mixed-methods study design was used. A qualitative study was conducted among 12 clinicians to gather relevant information regarding their practices in BBN of oral cancer diagnosis using a descriptive-interpretive approach. The themes that emerged were preparation for BBN, BBN setting, communication, emotional aspects, and summarizing the session. These themes were used to develop a questionnaire with 34 items. In the quantitative study, this questionnaire was sent to 87 clinicians who had experienced BBN of oral cancer diagnosis in the past 5 years; the response rate was 100%. An arbitrary cut-off score between the third and fourth quartiles was set to distinguish 'good' and 'poor' practice in BBN among the clinicians. The data analysis was performed using IBM SPSS Statistics version 23.0. Overall, at least two-thirds of the clinicians had good practices in BBN of oral cancer diagnosis. The clinicians' designation (oral and maxillofacial surgery consultant/specialist vs dental officer) and BBN experiences were factors associated with their practices in BBN of oral cancer diagnosis.