OBJECTIVE To determine the incidence and risk factors for leptomeningeal metastasis after surgery for brain metastasis of solid tumors. METHODS Review of the records of all patients operated on for brain metastasis between January 1990 and August 1995. RESULTS In this period 28 patients underwent surgery for brain metastasis, of whom 27 were available for evaluation in this study. Median survival after craniotomy was 11 months. Nine patients (33%) developed leptomeningeal metastasis 2-13 months after surgery, which included six of the nine patients operated on for posterior fossa metastasis (p=0.05). In five patients, leptomeningeal metastasis was the only site of recurrence. Three patients developed the leptomeningeal metastasis as bulky tumour along the spinal cord, which is a rare presentation. No other risk factors for the development of leptomeningeal metastasis other than surgery for posterior fossa metastasis were identified. CONCLUSIONS There is an increased risk of leptomeningeal metastasis after surgery for posterior fossa metastasis. Future trials should consider the value of an active approach to this complication in these patients.