For patients presenting with bilateral end-stage degenerative hip disease, the decision to perform arthroplasties simultaneously under a single anesthetic or staged remains controversial. Factors influencing staging include patient and physician preferences, comorbidities, and symmetry of disease progression. A consecutive series of 277 patients undergoing primary cementless bilateral total hip arthroplasty in lateral decubitus position is retrospectively reviewed to compare perioperative risks in simultaneous versus staged procedures. Procedures were performed simultaneously in 167 patients and staged in 110 at an average 8.1 months apart. Preoperative clinical scores were similar between groups; however, staged patients were significantly older (57 vs 52 years old; P < .0001) and were more likely to be Charnley class C (38% vs 14%; P = .0000) and female (57% vs 40%; P = .0051). Cumulative single-day blood loss and total blood units transfused per patient were significantly higher in simultaneous patients (479 vs 240 mL; P < .0001 and 0.8 vs 0.4 units; P = .0004), whereas cumulative length of stay was lower (3.9 vs 5.6 days; P < .0001). Inpatient adverse events per admission were more common in the simultaneous group (71.3% vs 42.3%; P = .0000). Fewer simultaneous patients met physical therapy goals by discharge (53.3% vs 79.5%; P = .0000), more required discharge to a rehabilitation facility (40.7% vs 18.6%; P = .0000), and more required subsequent hip surgery (3.9% vs 0.5%; P = .0116), predominately related to wound problems and dislocation. Although accomplishing 2 hip reconstructions under a single anesthetic provides shorter cumulative length of stay, closer examination of perioperative risks demonstrates that staged procedures done in the lateral decubitus position may be safer for the patient.