OBJECTIVES: To investigate the radiographic changes of two different particle sizes of deproteinized bovine bone mineral (DBBM) following lateral sinus floor elevation (LSFE) with simultaneous implant placement. MATERIALS AND METHODS: A total of 104 patients with 128 implants receiving LSFE with simultaneous implant placement were included and divided according to the grafted DBBM: 47 using small particle sizes (0.25-1 mm), 57 using large particle sizes (1-2 mm). Cone beam computed tomography (CBCT) images were taken at three points (T0: before surgery, T1: immediate postoperative, T2: 6-month postoperative). The two-dimensional and three-dimensional augmentation parameters, including apical bone height (ABH), endo-sinus bone gain (ESBG), peri-implant bone height (PBH), marginal bone loss (MBL), and augmented bone volume (AV) were measured. The differences in augmentation parameters between the small and large particle sizes of DBBM were compared. RESULTS: AV was 916.76 (657.88-1243.74) mm CONCLUSIONS: The augmentation outcome decreased after LSFE with simultaneous implant placement at the 6-month follow-up. Using the large particle size of DBBM improved the augmentation stability.