Management of periprosthetic femoral fractures is often complex, and few studies have documented its associated mortality. We retrospectively identified from our trauma and surgical registries 106 patients who underwent surgery for a periprosthetic femoral fracture. We then identified a contemporaneous age and sex-matched control cohort of 309 patients who had a hip fracture (femoral neck or intertrochanteric) and 311 patients who underwent primary hip or knee replacement. Mortality at one year was identified with use of the Social Security database. Twelve (11%) of 106 patients died within one year following surgical treatment of a periprosthetic fracture. During the same follow-up period, fifty-one (16.5%) of 309 patients died following surgery for a hip fracture and nine (2.9%) of 311 patients died following primary joint replacement. The mortality rate after a periprosthetic femoral fracture was significantly higher (p < 0.0001) compared with that for matched patients who had undergone primary joint replacement, and it was similar to the mortality rate after a hip fracture. For periprosthetic fractures, a delay of greater than two days from admission to the time of surgery was associated with an increased mortality rate at one year (p < 0.0007). Forty-nine patients underwent revision arthroplasty for the treatment of a Vancouver type-B periprosthetic fracture, and six (12%) died. In contrast, twenty-four patients with a Vancouver type-B periprosthetic fracture were treated with open reduction and internal fixation and eight (33%) died. The difference was significant (p < 0.03). The mortality rate within one year following surgical treatment of periprosthetic femoral fractures is high and is similar to that after treatment for hip fractures. Because revision arthroplasty for the treatment of type-B periprosthetic fractures was associated with a one-year mortality rate that was significantly less than that after surgical treatment with open reduction and internal fixation, in instances when either treatment option is feasible, revision arthroplasty may be the preferred option.