The timing of Pavlik harness removal in patients with developmental dysplasia of the hip is typically determined by clinical examination. Ultrasound is considered more sensitive than clinical examination in diagnosis of instability of the hip, but it is not routinely used in cases of developmental dysplasia of the hip, especially when determining the timing of Pavlik harness removal. The purpose of this study is to investigate if ultrasound examination is more effective than clinical examination alone in determining completion of Pavlik harness treatment. Fifty consecutive infants with developmental dysplasia of the hip were given both a clinical examination and dynamic ultrasound examination to determine if Pavlik harness treatment could be discontinued. A pediatric orthopedist conducted the physical examinations. Both a radiologist and a pediatric orthopedist interpreted the ultrasounds. Cost estimates for ultrasound and operative procedures were obtained at our institution and compared. The average age at the time of Pavlik harness placement was 5.3 days, and the average age at the time of ultrasound was 54.3 days. There were 35 females and 15 males and 31 left hips, 4 right hips, and 15 bilateral hips. All 50 patient hips were deemed clinically stable prior to obtaining an ultrasound. The ultrasound interpretations by a radiologist and pediatric orthopedist were in agreement in all cases. In one case, the ultrasound results did not correlate with results of the clinical examination. In that one case, the hip was clinically stable, but dynamic ultrasound revealed that the hip was located, but dislocatable. The Pavlik harness was reapplied to the patient for an additional 42 days. At 1-year follow-up the hip is stable and developing normally as determined by radiographs. The cost comparison revealed that the cost of 50 ultrasounds is less than the cost of a single operative procedure. The use of ultrasound to determine the timing of Pavlik harness cessation is justified from both a financial and a patient outcome perspective in this small study. Larger studies are needed before ultrasound examination used to help determine Pavlik cessation is considered standard of care.