The favorable clinical effects of water-soluble form of chlorophyll-a in the treatment of patients with chronic relapsing pancreatitis are described. 1) 34 cases were treated with chlorophyll-a infusion and fairly favorable effect was obtained in 23 cases and some favorable effect, in 9 cases. 2) The most disgusting symptom of pancreatitis, the abdominal pain disappeared in a week or so with infusion of 5--20 mg of chlorophyll-a per day for 1--2 weeks, in all the effective cases. 3) Patients have become well controlled by intermittent administration of chlorophyll-a, even when they had recurrences. 4) 5 cases which had difficulty in the treatment by trasylol, were also successfully treated with chlorophyll-a. 5) In all the cases treated with chlorophyll-a, no unfavorable side-effect, such as of allergic, or photosensitive, or hepatotoxic nature, was hitherto observed.