Background A relatively high percentage of monoblock metal-on-metal total hip arthroplasties (THAs) undergo early revision. Revision of these THAs poses challenges unique to this implant type. The early complications after these revisions remain unreported as do the clinical and demographic factors associated with these complications. Questions/purposes We describe (1) the frequency of early complications after revision of monoblock metal-onmetal THA; and (2) the clinical and demographic factors associated with complications. Methods A review of our institution's total joint registry identified 107 patients who underwent 114 revisions of monoblock metal-on-metal THAs. Mean patient age at revision was 60 years (range, 17-84 years), and 65% of the patients were women. Mean followup after revision was 14 months (range, 0-122 months). Revision diagnoses included metallosis (51%), aseptic loosening (27%), infection (7%), pain (6%), malposition (4%), instability (3%), iliopsoas impingement (2%), and periprosthetic fracture (1%). Major complications (instability, infection, aseptic loosening, and wound complications) were documented and included in the analysis. Minor postoperative complications such as urinary tract infection were excluded. Results Twenty-three of 114 procedures (20%) involved at least one early complication after revision of monoblock metal-on-metal THA with 18 (16%) undergoing at least one additional subsequent surgery. The most common complications included aseptic loosening (6%), deep infection (6%), dislocation (4%), and acetabular fracture (3%). Patients who sustained a complication after revision