CMOS integration creates the possibility of rendering complex imaging systems into low-cost wearable form factors with the potential to transform medicine through continuous monitoring in a point-of-care setting. The proven safety of ultrasound, its efficacy in soft-tissue imaging, and the integration of electronic systems-on-chip have independently led to the development of active front-end ASICs for handheld ultrasound systems [1]–[4] and passive mechanically flexible 2D transducer arrays tethered to large external electronics [5]. In this work, through innovation in design and packaging, we combine these approaches to produce a mechanically flexible 2D 1024-element 5-MHz wearable ultrasound device (Fig. 1) with a focal depth of up to 3.5 cm that conforms to the surface of the body.