In Insurance Institute for Highway Safety (IIHS) testing, the ES 350 achieved top 'good' scores in frontal and side impact, as well as the new roof strength test, but in rear impact (seat-based), it got a low 'marginal' rating--indicating a higher chance of whiplash injuries.
The federal government hasn't rated the ES 350 in its latest NCAP test system, and with the related Camry recently redesigned and a new ES expected next year, it likely won't be.
Safety equipment in the 2012 ES 350 is great; ten airbags (including rear side bags), anti-lock brakes with electronic brakeforce distribution, and stability control are all standard. All ES models additionally get the Safety Connect system, which uses cellphone technology and GPS transceivers to provide Automatic Crash Notification, Stolen Vehicle Location, emergency assistance (through an SOS button), and Roadside Assistance services. A 24-hour call center aids roadside assistance.
Also available in the ES is an Adaptive Cruise Control system, which uses radar to keep a safe distance behind the vehicle ahead; it also includes a useful (and potentially collision-avoiding) Pre-Collision System that will sound a warning, tighten seatbelts, and activate the brakes.