17 patients with advanced low-risk breast carcinoma not previously pretreated by cytostatic agents were treated by Vinorelbine (VIN), 5'-Nor-anhydro-vinblastine, a new semisynthetic compound of the vinca alkaloid series. A dose of 130 mg per week was administered in a hard gelatine formulation for at least eight weeks. Out of 15 evaluable patients, no complete or partial remission was observed. However, there were 9 patients (60%) achieving no change and tumor stabilization, respectively, lasting for a median of 3.0 months. Main toxicities were leukopenia (17.7%, WHO grade 3-4), nausea and vomiting (17.7%, WHO grade 3-4), and acute diarrhea (70.6%, WHO grade 1-4). Thus, further trials with the oral medication used for this study are not recommended.