INTRODUCTION: This study aimed to investigate the knowledge, attitudes and perceptions (KAP) of advance care planning (ACP) among specialist healthcare professionals (HCPs) in neurology, neuro-oncology and surgery. METHODS: This was a cross-sectional study of HCPs in Singapore. A standardised questionnaire was developed using validated questionnaires from the international literature, concepts of the Theory of Planned Behaviour and consultation with multidisciplinary palliative care specialists. The 45-item questionnaire included sections on sociodemographics, ACP experience and practices, ACP Knowledge, ACP Attitudes, ACP Perceptions and ACP Engagement. RESULTS: A total of 114 doctors, nurses and allied health professionals (AHPs) responded to the survey. Neurological, neuro-oncological and surgical HCPs generally have positive KAP towards ACP, but confidence to advocate for and conduct ACP could be improved. Doctors scored higher on KAP and intentions to engage in ACP as compared to nurses and AHPs. Significantly more doctors and nurses had attended formal ACP training than AHPs, while more doctors had conducted ACP conversations than nurses and AHPs. Attitudes towards ACP were independently and significantly associated with willingness to advocate for ACP, while perceptions of ACP, perceived relevance of ACP and readiness to engage in ACP were independently and significantly associated with both willingness and confidence to advocate for and to conduct ACP. The most common barriers to ACP among HCPs were disinterest or distress of patients and families and the lack of time. CONCLUSION: Enhanced ACP support, such as protocols, supervision and training, could improve ACP practice and engagement among specialist HCPs.