The aim of this study was to evaluate the success of one-stage implants placed at the time of alveolar bone augmentation using simultaneous guided bone regeneration technique with a collagen barrier membrane in patients suffering from insufficient bone width. Seventeen patients were treated with 20 one-stage OSTEOFIX (Oulu, Finland) implants using simultaneous guided bone regeneration technique. Dehiscence defects were filled by bovine bone mineral Bio-Oss and covered with collagen membrane. Clinical and radiographic parameters of the peri-implant conditions were assessed at the moment of prosthesis placement and at 1- and 5-year follow-ups. Diagnostic dehiscence defect measurements after implant placement showed that the mean vertical defect varied from 3.8 mm to 10.0 mm. At the moment of prosthesis placement and at 1- and 5-year follow-ups all implants were stable, painless and without biological complications. Clinical and radiographic parameters of the peri-implant conditions remained stable during follow-up. The cumulative implant survival rate was 100% after the 5-year observation period and the success rate for all pooled implants was 90%. The present study showed predictable treatment outcomes recorded after 5 years of function for one-stage OSTEOFIX (Oulu, Finland) oral implants placed simultaneously with guided bone regeneration using collagen membrane and deproteinized bovine bone mineral.