Police officers said an “altercation” happened at approximately 20:00 on Sunday at Wellington Park Estate, followed by a second “incident” at 22:30.
Two men, who are believed to know each other, both suffered stab wounds that required surgery at the General Hospital.
Both have been arrested on suspicion of grave and criminal assault and other offences related to the incident, and remain in hospital in a stable condition.
A Jersey Police spokesperson said: “The area is currently closed to traffic whilst crime scene investigators and search officers continue to collect evidence.
“House-to-house enquiries are being conducted as well as other investigative enquiries.”
Anyone who has any information or who can help with this investigation is asked to contact police on 612612 (option 2 then option 4) or the independent charity Crimestoppers anonymously on 0800 555 111 or via their anonymous online form.