Background and Objectives: The aim of this study is to evaluate the usefulness of Magnetic Resonance Imaging (MRI) for planning surgery and postoperative control of complex cases of abdominal wall hernia. Methods: Included in a prospective data base with more than 350 patients treated in two centers, a prospective study over ten patients with complex incisional hernias was designed. In all cases, preoperative diagnosis study and postoperative imaging control by MR Imaging were established. In the early and late follow-up controls, local and general complications were specifically noted and studied by MRI in each case. Results: The preoperative MRI was effective method for an adequate understanding of the defects and hernia sack content. In the postoperative control, the MRI was useful in the follow-up of the mesh integration, detection of complications and diagnosis of the relapsing. Conclusion: In our experience the MRI test is specially recommended in the preoperative workup of complex cases of incisional hernia.