Ultrasound has become a useful adjunct to many procedures performed in rehabilitation medicine. It has the advantages of cost-effectiveness, lack of radiation, and readiness of use and the ability to make dynamic examinations possible compared with other imaging tools. Through dynamic examinations, needles can be guided accurately to the target sites to increase the success rates of aspiration and injection procedures. At present, ultrasound-guided caudal epidural, sacroiliac joint, piriformis muscle, and hip-joint injections are commonly practiced in rehabilitation medicine. Perhaps the only disadvantage of ultrasound-guided injection technique is the long learning curve that is required for the physiatrists to be well acquainted with the simultaneous manipulation of ultrasound transducers, placement of needles, and the correct interpretation of musculoskeletal sonographic images. This is the first of two review articles on ultrasound-guided injections. This article will review the selected ultrasound-guided injection techniques that are performed in the low-back and hip-joint areas. Sonographic images and schematic illustrations of these ultrasound-guided injection techniques will be shown.