At 8.13am yesterday police were called to Bexley Grove, Harehills, where a man had been found with stab wounds.
He was taken to hospital by ambulance for emergency treatment and is in a critical condition.
Three men, aged 41, 48 and 52, have been arrested in connection with the incident and are in custody.
A cordon in in place around the scene in Bexley Grove to undergo forensic examination and enquiries are ongoing.