The 18th ACH4 annual scientific workshop was held in conjunction with Living Positive Victoria mHIVE World AIDS Day Symposium at the Doherty Institute, Melbourne, Vic from 29 November-2nd December 2023. The meeting was organised by Joanne Reidy, Michael Roche, Anna Hearps, Kirstie Bertram, Purnima Bhat, Arun Abayasingam, Lindi Masson, Youry Kim and David O’Keeffe. The ACHV awards at this meeting were won by Laura McCoullagh (Conference Attendance Scholarship), Henrik Zhang (Conference Attendance Scholarship), Gabriela Wu (Rob Dixon Award), Eloise Kershler (Domestic Travel Award), Harout Ajoyan (Domestic Travel Award), Arun Abayasingam (Chris Burrell Award) and Dishen Corey Chen (Yvonne Cossart Award).