The introduction of mammography screening and improvements in diagnostic tools resulted in a major increase of breast cancers detectable as small, nonpalpable lesions suitable for breast-conserving treatment. Accurate preoperative localization of these cancers is a necessity. Several methods are available for localization, of which wire-guided localization is considered the current gold standard. Promising techniques are radio-guided occult lesion localization, radioactive seed localization and ultrasound-guided surgery. In this article, an overview of the various localization techniques is provided, describing advantages, shortcomings and effectiveness.