Iliotibial band syndrome (ITBS) is caused by irritation from the iliotibial band repetitively passing over the lateral femoral condyle during flexion and extension. This study evaluated the efficacy of two ITBS treatments: phonophoresis using ultrasound to transport 10% hydrocortisone into subcutaneous tissues, and knee immobilization. Students in Basic Underwater Demolition/SEAL training diagnosed with ITBS were randomly assigned to group P (n = 13) receiving phonophoresis or group I (n = 13) receiving knee immobilization. Both groups received rest, ice, stretching, and ibuprofen. Subjects were examined daily until pain free. Endpoint was defined as running 1 mile on a treadmill without pain or stiffness. Group P was pain free on examination sooner (2 versus 8 days; p≤0.001). A greater (p≤0.005) proportion of subjects from group P (100%) recovered in less than 10 days than from group I (62%). One subject from group P and three from group I experienced pain during the 1‐mile run.