When responding to a suddenly appearing stimulus, we are slower and/or less accurate when the stimulus occurs at the same location of a previous event, as compared to when it appears in a new location. This phenomenon, often called Inhibition of Return (IOR), has fostered a huge amount of research in the last 20 years. This special issue will provide the reader with state-of-the-art information about the current debate on the functional mechanisms and the neural bases of IOR, and will thus become a reference for research on spatial attention.