Abstract. Forty‐one patients with ovarian cancer were investigated for the effect of cyclophosphamide stoss therapy on liver function. The patients were tested for serum bilirubin, alkaline phosphatase, aminotransferases (GOT, GPT) serum total proteins, and ten of them also underwent an intravenous galactose tolerance test. Serum total protein was found to decrease significantly during the cyclophosphamide stoss therapy. It was further noted that the number of pathological results for serum total bilirubin, alkaline phosphatase, GOT, and GPT increased during the treatment, whereas the number of pathological half‐lives of galactose tolerance decreased. Fifteen patients underwent 19 intramuscular Homactid tests before the beginning of cyclophosphamide stoss therapy and one and two weeks after the therapy. The responsiveness of the adrenal cortex two weeks after the therapy was found to be lower and shorter in duration, compared with the results obtained before the therapy. Cyclophosphamide stoss therapy was not found to cause any serious disorders of hepatic or adrenocortical function.