Peripheral T-cell lymphoma (PTCL) and natural killer (NK) cell lymphoma have poor survival with conventional cytotoxic chemotherapy. Because angiogenesis plays an important role in the biology of PTCL, a fully humanized anti-vascular endothelial growth factor (VEGF) antibody, bevacizumab (A), was studied in combination with standard cyclosphosphamide, doxorubicin, vincristine and prednisone (CHOP) chemotherapy (ACHOP) to evaluate its potential to improve outcome in these patients. Patients were treated with 6-8 cycles of ACHOP followed by eight doses of maintenance A (15 mg/kg every 21 days). Forty-six patients were enrolled on this phase 2 study from July 2006 through March 2009. Forty-four patients were evaluable for toxicity and 39 were evaluable for response, progression and survival. A total of 324 cycles (range: 2-16, median 7) were administered to 39 evaluable patients and only nine completed all planned treatment. The overall response rate was 90% with 19 (49%) complete response/complete response unconfirmed (CR/CRu) and 16 (41%) a partial response (PR). The 1-year progression-free survival (PFS) rate was 44% at a median follow-up of 3 years. The median PFS and overall survival (OS) rates were 7.7 and 22 months, respectively. Twenty-three patients died (21 from lymphoma, two while in remission). Grade 3 or 4 toxicities included febrile neutropenia (n = 8), anemia (n = 3), thrombocytopenia (n = 5), congestive heart failure (n = 4), venous thrombosis (n = 3), gastrointestinal hemorrhage/perforation (n = 2), infection (n = 8) and fatigue (n = 6). Despite a high overall response rate, the ACHOP regimen failed to result in durable remissions and was associated with significant toxicities. Studies of novel therapeutics are needed for this patient population, whose clinical outcome remains poor.