The high-pressure water jet cutting method, which uses a high-pressure water stream to cut hard materials, is widely used because it does not generate sparks or dust. However, once the high-pressure water jet is accidentally fired at a human body, a large amount of water containing abrasive materials flows into the body in a short time, causing severely contaminated injuries (Dailiana et al., 2008 [1]). Water jet injury (WJI) should be treated as a surgical emergency, but the severity is often underestimated, and treatment is delayed because the wound often shows only small holes [1]. Previous reports have shown that the majority of WJI occur in the extremities [1] (Rodríguez et al., 2019 [2]). On the other hand, abdominal and thoracic WJIs have been rarely reported, with only two cases of thoracic WJI [2]. Here, a case of thoracic WJI in which the patient was brought to our hospital the day after injury and treatment intervention was delayed is presented, and points to consider in the diagnosis and treatment strategy for WJI to the chest are discussed.