The deceased was identified as 33-year-old Rajeev Rajendran, from Tamil in Sri Lanka.
Manus Provincial Police Commander, Chief Inspector David Yapu, said the deceased was admitted at the hospital and was receiving treatment for self-inflicted wounds when he hung himself between the hours of 2am and 4am on Monday.
He was in hospital after he attempted to kill himself by using a razor blade to cut his throat.
Whilst admitted, he hung himself in the laundry building of the hospital.
A forensic team from Port Moresby attended to the scene and retrieved his body.