Purpose: To retrospectively compare three-dimensional ultrasonography (3D-US) and pelvic X-rays to assess the position of tubal sterilization microinserts. Material and methods: Forty-four patients who underwent tubal sterilization with Essure (R) microinserts in our institution were included. The microinserts'position was evaluated three months after the procedure using 3D-US and pelvic X-rays. Placement on 3D-US was binary categorized as correct or incorrect and the distance between the two devices was reported. The orientation and symmetric deployment of the microinserts and the distance between the proximal parts of the two devices was assessed on pelvic X-rays. Performance of 3D-US and pelvic X-ray were compared using Mac Nemar test. Comparison of the distance between the two devices measured on pelvic X-rays and 3D-US was made with the paired Student t test. Results: 3D-US images showed microinserts in 93% (41/44). Eighty-six percent (38/44) were correctly positioned on 3D-US and 82% (36/44) on pelvic X-rays. No significant differences between the performances of the two imaging techniques were found. No significant differences for the distance between the two devices measured on pelvic X-ray and 3D-US was found. Conclusion: 3D-US is a simple, non-ionizing technique, which appears as a promising alternate technique to pelvic X-rays to assess the correct position of Essure (R) microinserts. (C) 2015 Editions francaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.