In an uncontrolled prospective study, 100 primary total hip arthroplasties (THAs) using the DF-80 implant were followed up for a minimum of 2 years with rigorous clinical and radiographic examinations to define the natural history of this prosthetic system. Three groups were identified: (I) hips requiring revision because of failure (n = 3); (II) "impending" failures with radiographic indices of loosening (n = 8); and (III) clinically and radiographically benign, stable implants (n = 89). The preoperative Harris hip score was similar for all groups. Postoperatively, the failure group demonstrated early progressive clinical and radiographic deterioration with surgical revision at an average of 33 months. Male sex, increased weight, and greater intraoperative hemorrhage correlated positively with failure. The impending-failure group developed limited radiolucencies in the later postoperative period. Calcar resorption was noted in 26% of the total population and heterotopic ossification in 46%. We conclude that this series of THAs using DF-80 implants included a subset of patients demonstrating early clinical failure and widespread aggressive bone-cement radiolucencies that required early surgical revision.