Chelsea management were pleased with the performances of their backup goalkeepers last season.
Both Hilario and Ross Turnbull saw action in the absence of Petr Cech during Chelsea's Double winning season.
Blues No2 Ray Wilkins told the club's website: "Hilario came into the team for some very big matches indeed and again did everything expected of him in Petr's absence. His professionalism is a credit to the club and himself.
"Not many people would have known much about Ross when he arrived here, but he has worked extremely hard with the other goalkeepers and impressed everybody with his mature performances when called upon."