Background: Rheumatological diseases can severely impair mobility and workability, with hip fusion being a significant complication. Bilateral total hip arthroplasty (THA) is often the last resort for these patients, yet its role in treating bilateral fused hips has been minimally explored in the literature. Objective: To evaluate the clinical outcomes of bilateral THA in patients from a low-income setting with bilateral hip fusion. Patients and Methods: This retrospective case series involved 16 patients with bilateral fused hips and some degree of mobility. Exclusion criteria included active infection or debilitating diseases. All patients underwent weight-bearing X-rays and subsequent bilateral THA using patient-specific instrumentation (PSI). Outcomes assessed included the Harris Hip Score (HHS), range of motion (ROM), pain in the hips, knees, and lower back, and leg length discrepancy. Results: The study included 16 patients (seven females), with an average age of 39.0 years (SD = 15.9). The most common causes of fused hips were rheumatoid arthritis and avascular necrosis (25% each). Significant improvements were observed postoperatively in HHS, ROM, hip and knee pain, lower back pain, hip deformity, and leg length discrepancy (p < 0.05). Two patients experienced minor postoperative complications, which resolved. Conclusion: Bilateral THA is a viable option for bilateral fused hips regardless of the etiology, sex, or age of participants.