A reinforced passenger compartment helps protect the occupants with front- and rear-crush structures. Seatbelt pretensioners and force limiters are used for the front and outboard rear seats. In addition to the advanced dual-front airbags and front seat-mounted side airbags, the Lexus Supplemental Restraint System (SRS) for the IS includes side-curtain airbags that extend from A-pillar to C-pillar, and a knee airbag for both the driver and the front passenger. The front passenger airbag features two chambers, creating an indentation in the center impact area that helps to provide overall occupant protection.

The IS 250 offers optional High Intensity Discharge (HID) headlamps with LED daytime running lamps. Lexus IS 350 models feature standard HID headlamps with LED daytime running lamps and headlamp washers. The rear back-up camera, included with the optional navigation system, automatically projects an image of what its lens can detect behind the car onto the navigation screen when the transmission is in reverse gear. The exterior mirrors integrate turn signals.

The optional Intuitive Park Assist (IPA) system uses ultrasonic sensors to detect objects close to the car's front and rear bumpers, helping to alert the driver and showing distance to objects in the multi-information display within the speedometer. When any IS model is also equipped with the optional navigation system, information on objects detected is shown in greater detail on that system's seven-inch touch screen display.