Police say the 49-year-old armed man barricaded himself inside a car in the Portapique area, about 40 kilometres west of Truro.
The standoff lasted most of the day while a crisis negotiator tried unsuccessfully to coax the man from his car.
Sgt. Alain LeBlanc says the man died shortly before 6 p.m.
He says the man was a suspect in the death of a 47-year-old woman, whose body was discovered at an apartment in Truro Heights earlier in the day.
No names have been released.
LeBlanc says the incident has been referred to the Nova Scotia Serious Incident Response Team for investigation.