Ultimate Spider-Man features the death of Peter Parker in issue #160. The issue concludes the “Death of Spider-Man” storyline, in which the teenage Peter Parker makes a final stand against Norman Osborn's Green Goblin and several escaped villains.
The story begins in Ultimate Spider-Man #156 and runs through #160, published from May to August 2011. After Osborn escapes S.H.I.E.L.D. custody and frees members of the Ultimate Six, Peter is drawn into a desperate battle despite being exhausted and badly injured. Mary Jane, Aunt May, Gwen Stacy, and other allies ultimately find him after the fight.
Peter dies after saving his loved ones, reinforcing the series' central theme that responsibility means protecting others even at terrible personal cost. His death changes the Ultimate universe and leads directly into the next series, Ultimate Comics: Spider-Man, where Miles Morales takes up the Spider-Man mantle.
The wording can cause confusion because the event is also called the “Death of Spider-Man” storyline, not simply the death of Peter Parker. Peter is later revealed to have survived through the effects of the OZ compound, but issue #160 is still the landmark issue depicting his apparent death.