Last year it was announced, Creators Guillermo del Toro and Chuck Hogan will end the series at the conclusion of the fourth season..
FX Networks president Nick Grad (of original programming), had this to say: "We sincerely thank Carlton Cuse, Guillermo del Toro, Chuck Hogan and their creative team as well as the fantastic cast for three exciting seasons of The Strain. Though we’re sad to see it go, we fully support the way in which they are crafting the fourth season’s dramatic conclusion."
From Executive producer Carlton Cuse: "Our original plan was for the series to last three years, once we began telling that story it expanded to be more. After finishing the writing on Season 3, Guillermo, Chuck and I looked at our remaining story and felt the best version could be told in one more season. We have a fantastic plan for an exciting and climatic Season 4. We are deeply grateful to FX for supporting our vision and for allowing us to end the show on our own timetable."