Peripheral T-cell lymphomas (PTCLs) have an aggressive biological course and poor clinical outcomes. Despite producing somewhat less-than-satisfactory results, the combination of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) remains the de facto standard in PTCL treatment. Addition of etoposide to CHOP backbone to overcome such unsatisfactory results has yielded contradictory information. We aimed to thoroughly analyze the impact of incorporating etoposide into first-line treatment. Using merged data from the Korean National Health Insurance Service and National Cancer Registry, a total of 1933 patients (median age, 58 years) were evaluated for clinical characteristics and treatment outcomes. Thirty-eight percent (n = 748) of the 1933 patients received CHOP or CHOP-like regimen, 35.1% (n = 678) received CHOP-like regimen plus etoposide, 5.9% (n = 113) received other backbone chemotherapy plus etoposide, and 20.3% (394) received other treatments in the first-line setting. When we divided the patients into 3 groups according to regimen (group 1, CHOP or CHOP-like regimen; group 2, CHOP or CHOP-like regimen plus etoposide; group 3, all others), group 1 was associated with longest progression-free survival (PFS; P < .001) and overall survival (OS; P < .001). This lack of benefit with etoposide addition was observed across different PTCL subtypes and age groups. Adding etoposide led to longer hospitalizations and cytopenias requiring more transfusion. Upfront hematopoietic stem-cell transplantation led to better OS. Addition of etoposide to CHOP-like regimens does not result in better PFS or OS for patients with PTCL. Overall, Asian patients with PTCL do not benefit from chemotherapy intensification of first-line treatment. We hereby provide crucial information on establishing standardized PTCL treatment.