The　aim　of　the　present　study　was　to　assess　the　clinical　outcomes　of　arthroscopic　synovectomy　in　adolescent　or　young　adult　patients　with　advanced　haemophilic　arthropathy.　From　January　2009-January　2012,　clinical　data　from　11　adolescent　or　young　adult　patients　with　advanced　haemophilic　arthropathy　who　were　treated　with　arthroscopic　synovectomy　were　retrospectively　collected.　The　mean　follow-up　period　was　71.91±5.28　months.　The　evaluated　indicators　included　frequency　of　joint　bleeding,　range　of　motion　(ROM),　X-ray　staging,　hospital　for　special　surgery　(HSS)　knee　score　and　HSS　pain　scores.　Joint　bleeding　frequency,　pain　degree　and　HSS　scores　significantly　improved　following　arthroscopic　synovectomy　at　the　end　of　the　follow　up　period.　The　ROM　did　not　significantly　improve.　Among　the　11　patients,　radiographic　stage　remained　unchanged　in　9　cases　whereas　the　remaining　2　cases　progressed　from　stage　IV　to　stage　V.　No　patients　required　total　knee　arthroplasty　through　the　end　of　the　follow-up　period.　These　findings　suggested　that　arthroscopic　synovectomy　appears　to　an　effective　treatment　option　to　decrease　the　frequency　of　bleeding　and　knee　pain,　improve　knee　function　and　delay　knee　joint　arthroplasty　to　a　certain　extent　for　adolescent　or　young　adult　patients　with　advanced　haemophilic　knee　arthropathy.