Magnetic resonance (MR) images in rabbit muscle were used to select a target region for application of pulsed-focused ultrasound. Liposomes encapsulating gadopentetate dimeglumine, an MR-detectable model representing pharmaceutical agents, were then injected intravenously. Focal enhancement on T1-weighted images, representing gadolinium-liposome accumulation, occurred in the pulsed-focused-ultrasound focal zone. Therefore, MR-guided pulsed-focused ultrasound targeted the delivery of macromolecular pharmaceutical agents within tissues.