Lapatinib is an oral, small-molecule, reversible inhibitor of both epidermal growth factor receptor and human epidermal growth factor receptor-2 (HER2) tyrosine kinases. In March 2007, the US Food and Drug Administration approved lapatinib for use in combination with capecitabine for the treatment of women with HER2-overexpressing, advanced or metastatic breast cancer. This review discusses the available information of lapatinib in Chinese breast cancer patients, focusing on its effectiveness and clinical application against advanced or metastatic breast cancer. In pivotal phase III trials, a combination of lapatinib and capecitabine significantly decreased the risk of disease progression compared to capecitabine alone in women with HER2-positive advanced or metastatic breast cancer. Other trials were used to evaluate lapatinib in combination with hormone therapy, in combination with trastuzumab, and as an adjunct to adjuvant therapy for early-stage disease. Preclinical data have revealed that lapatinib is active in trastuzumab-resistant cell lines as well as synergistic with trastuzumab. In clinical trials, lapatinib has not been associated with serious or symptomatic cardiotoxicity. Further, it can cross the blood-brain barrier and may therefore have a role in preventing cancer progression in the central nervous system. Thus, lapatinib warrants further evaluation in HER2-positive metastatic and early-stage breast cancer patients.