The treatment of the infected total hip replacement remains expensive, leads to a long difficult course for the patient, and frequently results in a suboptimal functional outcome. Various treatment techniques are available, and may be suitable for the more straightforward case. These include one-stage exchange arthroplasty, two-stage exchange arthroplasty, resection arthroplasty, and debridement and irrigation. The complex infected total hip replacement encompasses numerous host and organism factors. These include unusual or multiple organisms, diagnostic difficulties, bone loss, immunocompromise, and reinfection. In the authors' experience, the problem of the complex infected hip replacement is best addressed using the prosthesis of antibiotic-loaded acrylic cement approach. This interval arthroplasty is a modular, custom-made, immediate fit, antibiotic selective, temporary spacer system that allows the surgeon to reconstruct even the most deficient bone stock safely and effectively using two-stage exchange arthroplasty. It affords the patient rapid pain relief, allows them to mobilize quickly while successfully eradicating infection in 96% of hips with severe bone loss, and sets an appropriate soft tissue environment for a relatively straightforward second stage procedure. The prosthesis of antibiotic-loaded acrylic cement system affords the benefits of two-stage exchange without the functional disadvantages of an excision arthroplasty particularly when the proximal femur is severely deficient. It allows flexibility for the interval period and the type of fixation used, and the potential for allograft reconstruction at the final stage.