Ischiofemoral impingement syndrome is an uncommon disorder defined by hip pain caused by the narrowing of the space between the ischial tuberosity and lesser trochanter with associated entrapment of the quadratus femoris muscle. We effectively treated two male patients using ultrasound-guided prolotherapy with polydeoxyribonucleotide sodium mixed with local anesthetics. A 24-year-old male patient with no history of trauma or surgery complained of bilateral hip and groin pain; magnetic resonance imaging demonstrated slight narrowing of the bilateral ischiofemoral spaces with mild enhancement of the left quadratus femoris muscle. A 23-year-old male patient with a history of iliotibial band release and iliopsoas tendon release complained of left hip and groin pain; magnetic resonance imaging revealed swelling of the left quadratus femoris muscle. After the fifth treatment session of prolotherapy, the pain severity score using the visual analog scale was found to be minimal (0-1/10), and follow-up magnetic resonance imaging revealed a slightly decreased enhancement of the quadratus femoris muscle compared with that on previous images. Prolotherapy with polydeoxyribonucleotide sodium was an efficacious treatment for two patients with ischiofemoral impingement syndrome who were not candidates for surgery.