Ice, compression and elevation are the basic principles of acute soft tissue injury. Few clinicians, however, can give specific evidence based guidance on the appropriate duration of each individual treatment session, the frequency of application, or the length of the treatment program. The purpose of this systematic review is to identify the original literature on cryotherapy in acute soft tissue injury and produce evidence based guidance on treatment. A systematic literature search was performed using Medline, Embase, SportDiscus and the database of the National Sports Medicine Institute (UK) using the key words ice, injury, sport, exercise. Temperature change within the muscle depends on the method of application, duration of application, initial temperature, and depth of subcutaneous fat. The evidence from this systematic review suggests that melting iced water applied through a wet towel for repeated periods of 10 minutes is most effective. The target temperature is reduction of 10-15 degrees C. Using repeated, rather than continuous, ice applications helps sustain reduced muscle temperature without compromising the skin and allows the superficial skin temperature to return to normal while deeper muscle temperature remains low. Reflex activity and motor function are impaired following ice treatment so patients may be more susceptible to injury for up to 30 minutes following treatment. It is concluded that ice is effective, but should be applied in repeated application of 10 minutes to be most effective, avoid side effects, and prevent possible further injury.