The study retrospectively determined the efficacy and safety of fixation of the pelvis (FFP) fragility fractures type IV using two tension band ilioiliac locking compression plates. Forty-one patients with FFP were treated in 2017–2020. 16 patients with FFP type IV, unable to walk weight-bearing, were treated by fixation using two tension band ilioiliac locking compression plates without fixing the anterior ring. Preoperatively and one year postoperatively, the functional outcome and performance were assessed using Pelvic Discomfort Index (PDI) and Timed Up and Go (TUG) test. Pre- and postoperative hemoglobin level was evaluated. Operation time and intra-and postoperative complications were documented. One year postoperatively, an X-ray was taken. The arithmetic mean (x) and standard deviations (±) of quantitative variables were calculated. T-test for dependent samples was used for pre-and postoperative results comparison. The PDI improved (p < 0.001) from x = 81.42 ± 4.04 to x = 36.19 ± 15.58. Preoperatively none of the patients was able to perform the TUG test. Postoperatively, the result exceeded x = 13.13 ± 3.99 s. The operation lasted x = 42.80 ± 8.90 min. Hemoglobin decreased (p < 0.001) from 11.63 ± 1.11 to 9.07 ± 1.21 g/dL. No complications nor fixation loosening were noted. The study support fixation using two tension band ilioiliac locking compression plates as an efficient and safe treatment of the FFP type IV.