This book constitutes the refereed proceedings of the 12th International ConferenceampampnbsponampampnbspHealth Information Science HIS 2023 held in Melbourne VIC AustraliaampampnbspduringampampnbspOctober 2324 2023.The 20 full papers and 9 short papers included in this book were carefully reviewed andampampnbspselected from 54 submissions. They were organized in topical sections as followsampampnbspDepression ampamp Mental Health Data Security Privacy ampamp Healthcare Systems Neurological ampamp Cognitive Disease Studies COVID19 Impact Studies Advanced Medical Data ampamp AI Techniques Predictive Analysis ampamp Disease Recognition Medical Imaging ampamp Dataset Exploration Elderly Care and Knowledge Systems.