Imaging is now central to the investigation and management of anorectal and pelvic floor disorders. This has been brought about by technical developments in imaging, notably, three-dimensional ultrasound and magnetic resonance imaging (MRI), which allow high anatomical resolution and tissue differentiation to be presented in a most usable fashion. Three-dimensional endosonography in anorectal conditions and MRI in anal fistula are two obvious developments, but there are others, with dynamic st- ies of the pelvic floor using both ultrasound and MRI coming to the fore. This atlas provides an easy way to gain a detailed understanding of imaging in this field. The atlas is divided into four sections covering the basic anatomy, anal/perianal disease, rectal/perirectal disease and functional assessment. One of the difficulties with developing an atlas is to strike the right balance - tween text and images. Too much text and it is not an atlas; too little text and the - ages may not be understood. The editors of this atlas are to be congratulated on achi- ing an appropriate balance. The images are all that one expects from an atlas, and the diagrams are excellent. The commentaries at the end of invited chapters are a valuable addition, placing what are relatively short, focussed chapters into context. They add balance and depth to the work and are well worth reading.