Background: A clinical phase II study with a topical formulation of hexadecylphosphocholine (Miltefosine solution 6%) was performed in patients with skin-metas-tasized or locally recurrent breast cancer. Material and Methods: 76 patients had entered the study. At study entry, skin metas-tases or local recurrences were progressive, newly diagnosed or recurrent in most cases and stable in a few. All patients were pretreated with up to 4 different standard treatment modalities (surgery, radio-, chemo- and endocrine therapy). 24/76 patients had to be excluded from response analysis due to changes in the systemic anticancer therapy prior to study entry or during the study period (12/24), due to early systemic tumor progression (5/24), refusal of treatment (2/24), insufficient documentation (3/24), male breast cancer (1/24), or performance status of WHO grade 3 at study entry (1/24). Results: Within the scheduled time for response assessment (2 months) remissions were achieved in a total of 12 out of 52 patients (1 CR, 11 PR). In patients with concomitant systemic antitumor therapy the response rate was 24% (7/29), while it was 22% (5/23) in patients without concomitant systemic antitumor treatment. In 52% of the patients (27/52) a stabilization of the skin infiltration (no change) was observed. The treatment was well tolerated by the majority of patients. In 2/74 patients treatment was discontinued due to pruritus. In 46/74 patients local adverse reactions were observed, presenting as pruritus, rash, dry skin, bleeding at ulcer/lesion and skin atrophy. Systemic adverse reactions (anorexia, nausea/vomiting, alopecia, stomatitis) were only seen in patients with systemic antineoplastic comedication. Conclusion: This phase II trial confirms results of a phase I trial showing that topically applied Miltefosine solution causes objective tumor response in skin-metastasized and/or locally recurrent breast cancer.