Hyundai Sonata is built from the ground up with safety in mind, with a hot stamped ultra-high-strength steel body structure, advanced airbag technology and Electronic Stability Control (ESC), delivering on Hyundai's commitment to both active and passive safety technology leadership. The prior generation Hyundai Sonata was the first midsize sedan with standard ESC when it launched in March of 2005. ESC was not standard equipment on Honda Accord until the 2008 model year and the 2010 model year for Toyota Camry. Once again every 2011 Sonata has lifesaving ESC as standard equipment. This is important because the National Highway Traffic Safety Administration (NHTSA) has reported that ESC results in 35 percent fewer single-vehicle crashes and 30 percent fewer single-vehicle fatalities in passenger cars.

The Hyundai Sonata also features a state-of-the-art braking package. The package includes four-wheel disc brakes and an Anti-Lock Braking System (ABS) including Brake Assist, which provides maximum braking force when a panic stop is detected, and Electronic Brake-force Distribution (EBD) to automatically adjust the braking force to front and rear axles based on the vehicle loading conditions.

Hyundai Sonata features six airbags—including dual front, front seat-mounted side-impact, and front and rear side curtain airbags—along with active front-seat head restraints. The 2011 Hyundai Sonata is projected to earn the NHTSA's top rating of five-stars for front and side impacts. Other passive safety features include shingle-style rear-seat head restraints for improved visibility, three-point seatbelts for all seating positions, front-seat seatbelt pretensioners and force limiters, and a rear-seat Lower Anchors and Tethers for Children (LATCH) system for child seats.