Preoperative or neoadjuvant chemotherapy is a well-established modality in the treatment of nonmetastatic breast cancer. Patients initially considered inoperable may be able to achieve operable status after preoperative chemotherapy and patients initially considered not to be candidates for breast conservation may convert to breast conservation status. Human epidermal growth factor receptor 2 (Her2)-positive tumors have been shown to have a more aggressive course including early local relapse and metastasis when compared to Her2-negative breast cancers, but the optimal use of Her2-targeted agents is constantly evolving as new agents become available. Preoperative studies allow us to quickly assess the activity of new agents and combinations for particular biological subsets of breast cancer.