This prospective case series evaluated the use of a resorbable natural collagen membrane with a mixture of autogenous bone and anorganic bovine bone- derived mineral (ABBM) for lateral ridge augmentation and subsequent implant placement. A mixture (1:1) of particulated autogenous bone and ABBM was used for lateral ridge augmentation and covered with a resorbable, natural collagen bilayer membrane to treat knife-edge ridges and prepare them for implant placement. Ridge measurements were obtained pre- and postsurgery, complications recorded, and biopsy specimens examined histologically. Seventysix implants were placed in 25 patients with 31 knife-edge ridge surgical sites. One defect had a bone graft complication (3.2%; exact 95% confidence interval: 0.1%, 16.7%). Clinical measurements revealed an average of 5.68 mm (standard deviation [SD] = 1.42 mm) of lateral ridge augmentation after a mean 8.9-month (SD = 2.1 months) graft healing period. Clinically, all treated ridges were sufficient in width for subsequent implant placement. All implants survived with an average follow-up of 20.88 months (SD = 9.49 months). Histologic analysis of nine surgical sites showed that ABBM was connected with a dense network of newly formed bone with varying degrees of maturation. Histomorphometric analysis demonstrated that autogenous bone represented a mean of 31.0% of the specimens, ABBM 25.8%, and marrow space 43.2%. The treatment of horizontally deficient alveolar ridges with the guided bone regeneration technique using autogenous bone mixed with ABBM and a natural collagen resorbable barrier membrane can be regarded as successful. Implant success and survival need to be confirmed with long-term follow-up examinations.