Key content Transperineal ultrasound allows reproducible imaging of pelvic floor conditions that aids in the thorough assessment required to diagnose and treat urogynaecological conditions. Views that can be obtained include two‐dimensional (2D) sagittal views of the bladder neck, urethra and pelvic floor; 2D coronal views of the anal canal; and three‐dimensional (3D) or four‐dimensional (4D) views of the genital hiatus and anal canal. This allows assessment of the post‐void residual volumes, detrusor wall thickness and dynamic assessment of the urethral morphology. Ultrasonographic assessment enables accurate information about maternal birth trauma to be ascertained, including levator ani muscle avulsion and obstetric anal sphincter injury. Transperineal ultrasound can be used to identify and assess previously implanted vaginal mesh and midurethral slings. Learning objectives To understand the role of ultrasound in clinical urogynaecology practice, including the assessment of slings and meshes. To know the ultrasound probes, techniques and views used to image the pelvic floor and anal sphincters by transperineal ultrasound. To describe assessment of the lower urinary tract, pelvic organ prolapse and obstetric anal sphincter injury using ultrasound. Ethical issues Thorough assessment of the pelvic floor is mandatory against the background of technological advances in the investigation of pelvic floor dysfunction. As a common and major complication of childbirth, maternal birth trauma must be assessed fully to support primary and secondary prevention. Thorough assessment must underlie the use of mesh implants, and dealing with sling and mesh complications is enhanced by imaging.