The fast developing field of RNA interference (RNAi) requires monitoring of small interfering RNA (siRNA) delivery to targeted organs and evaluating the efficiency of target gene silencing. The molecular imaging approach fits perfectly to fulfill these needs and provides information in a fast, reproducible, and noninvasive manner. This review serves as a first attempt to summarize existing information on various imaging modalities and their application for siRNA imaging. It is noteworthy that new publications in this field appear almost on a weekly basis and the authors have made a sincere attempt to reflect the development of this area in their review.