Neurolytic splanchnic nerve block is a relatively safe and effective method for the relief of intractable pain caused by upper abdominal cancer. We have experienced a case of severe acute respiratory failure during splanchnic nerve block under control of X-ray fluoroscopy. We think that the most likely cause of the acute respiratory failure was an asthmatic attack due to anxiety and dyspnea from the injury or stimulation of the diaphragm and pleura in this case.