Capecitabine plus lapatinib combination is an effective chemotherapy regimen in patients with advanced breast cancer. Neurological adverse effects secondary to this regimen were reported rarely in literature. A woman with breast cancer presented with complaints of slurred speech while using the capecitabine and lapatinib combination. Her major complaint was slurred speech. No other radiologic or laboratory disorders were detected in the patient. Slurred speech improved one week after the capecitabine and lapatinib combination was discontinued without any further intervention.