Lumbar incisional hernias (LIH) are a rare wall defect, whose surgical management is challenging because no recommendation exists. Moreover, LIH are frequently associated with flank bulging which should be taken into account during LIH surgical repair. We aimed to describe a cohort of patients operated on for LIH using a homogeneous surgical technique and to report surgical outcomes. The records of all consecutive patients operated on in a specialized surgical center between January 2009 and January 2015 were retrospectively reviewed. The same open technique was performed, i.e., using a mesh into the retroperitoneal space posteriorly, placed with the largest overlap inferiorly and posteriorly, and fixed through the controlateral abdominal wall muscles under strong tension to correct the flank bulging. The cohort included 31 patients, of median age 62, who presented two or more comorbidities in 68% of cases. LIH was recurrent in 45% of patients, and was related to nephrectomy in 61% of patients. The mesh was totally extraperitoneal in 65% of patients. The postoperative mortality rate was null. The rate of specific surgical complications was 32.3%, and the rate of overall postoperative morbidity (Clavien-Dindo classification) was 38.7%. After a median follow-up of 27.5 months, the recurrence rate was 6.5% and 9.7% reported chronic pain. The open approach for LIH repair was safe and enabled treating flank bulging simultaneously in all patients. Due to the paucity of adequate scientific studies, this reproducible open method could help moving toward a standardization of LIH surgical management.