Chronic muscle and tendon injuries to the groin are common sports injuries. The symptoms of groin injuries are often uncharacteristic which can result in a delay in the correct and specific diagnosis being reached. The most common injury is the overuse strain resulting in chronic tendinitis of the adductor muscle/tendon units, especially the adductor longus. The rectus femoris and rectus abdominous muscles and tendons are also commonly affected. Computed tomography, magnetic resonance imaging and ultrasonography have been widely adopted to diagnose muscle/tendon injuries to the groin. Ultrasonography has been shown to be accurate and sensitive in diagnosing tendon injuries in the groin region, especially small partial ruptures of the muscle/tendon unit. Ultrasonography has the advantage of being fast, inexpensive and widely available. Normal findings are readily distinguished from pathological findings providing valuable pre-operative information, such as location and extent of the injury. The differential diagnoses are many and often difficult to reach. The most commonly overlooked differential diagnoses are chronic prostatitis and hernias. A multidisciplinary approach is valuable in many cases. The recommended treatment is well planned and gradually increased rehabilitation programme during the first stages. Surgery for acute injuries is rarely indicated. Surgery, for example tenotomy of the adductor longus, has given satisfactory results in many athletes when nonsurgical treatment has failed.