Abstract This article is a review of the development and application of aptamer probes for cell imaging. Aptamers selected against whole cells have been modified with different fluorescent dyes and nanomaterials, such as gold nanoparticles, quantum dots, and superparamagnetic iron oxide, for their use as imaging probes of live cells. These probes have been successfully used for cell imaging both in vitro and in vivo by optical imaging, magnetic resonance imaging (MRI), computed tomography (CT), and positron‐emission tomography (PET). In this article, we discuss the development of different aptamer‐based probes currently available for imaging of live cells and their applications in the biomedical field. WIREs Nanomed Nanobiotechnol 2011 3 328–340 DOI: 10.1002/wnan.133 This article is categorized under: Diagnostic Tools > In Vitro Nanoparticle-Based Sensing Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Nanotechnology Approaches to Biology > Nanoscale Systems in Biology