Peripheral T cell lymphoma (PTCL) is a heterogeneous group of aggressive neoplasms with poor outcomes, commonly affecting elderly patients with comorbidities. This study aims to describe outcomes of elderly PTCL patients in a large international cohort. Patients aged ≥ 70 years with PTCL diagnosed from January 1, 2010 - December 31, 2015 in the Swedish Lymphoma Registry (SLR) and California Cancer Registry (CCR) were identified. Data on comorbidity were retrospectively collected according to the Charlson Comorbidity Index (CCI) and clinical outcomes were extracted. 891 patients were included (SLR, n = 173, CCR, n = 718). Median age was 77 (SLR) and 78 (CCR) years. Included subtypes were AITL, n = 226; ALCL, n = 122; EATL, n = 31; Hepatosplenic TCL, n = 7; NK/T-cell lymphoma, n = 62; and PTCL NOS, n = 443. CCI data was available in 775 patients (87 %), and CCI scores were divided into the groups CCI = 0 (39 %), CCI = 1 (22 %) and CCI > 1 (39 %). Median age did not differ between the CCI groups (p = 0.72). Patients with a CCI > 1 had a worse median overall survival (OS) (4.4 months) compared to patients with CCI = 0 (11.9 months) and CCI = 1 (8.4 months), p < 0.001. Comorbidity and advancing age in as little as 5-year increments are important adverse factors in this group. The majority of patients died of lymphoma within a year from diagnosis, underscoring the importance of developing new treatments.