Quantum dots (QDs), nanometer-sized fluorescent probes with unique optical and electronic properties, offer a promising and powerful tool for cancer imaging and diagnostics. For the past few years, QDs were actively developed for biomolecular profiling of cancer biomarkers, in vivo tumor imaging, and even targeted drug delivery. These emerging applications are currently being improved and integrated into clinical practice. In this article, we describe the development of multifunctional QDs and their potential applications in oncology, with a particular emphasis on the diagnosis, prognosis, and treatment of urologic cancers.