Graduated from the University of Melbourne in 1976. His qualifications include M.B.,B.S.(Melb), F.R.A.C.G.P, B.Ed(LaTrobe), D.R.A.N.Z.C.O.G. In the past he has been on the visiting medical staff of Springvale, Dandenong, Mordialloc and Moorabbin hospitals and has been the Chelsea Medical Officer of Health.

Dr Demediuk is specialises in vasectomy procedures, neonatal circumcision, skin cancer detection and surgery. He also practices aviation medicine (he is a member of the Aviation Medical Society and is a Designated Aviation Medical Examiner for the Civil Aviation Safety Authority) and continues his interest in obstetrics.

He is an accredited shared care obstetrics provider to Dandenong, The Mercy, The Royal Women’s and Sandringham Hospitals and to the Monash Medical Centre.