Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of aggressive neoplasms with poor outcomes, commonly affecting older patients with comorbidities. This study aims to describe outcomes of older patients with PTCL in a large international cohort. Patients aged ≥70 years with PTCL diagnosed from 1 January 2010 to 31 December 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. A total of 891 patients were included (SLR, n = 173; CCR, n = 718). Median age was 77 (SLR) and 78 (CCR) years. Included subtypes were as follows: angioimmunoblastic T-cell lymphoma, n = 226; anaplastic large-cell lymphoma, n = 122; enteropathy-associated T-cell lymphoma (EATL), n = 31; hepatosplenic TCL, n = 7; natural killer-/T-cell lymphoma, n = 62; PTCL not otherwise specified, n = 443. CCI data were 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 among the CCI groups (P = .72). Patients with a CCI > 1 had a worse median overall survival (4.4 months) compared with patients with CCI = 0 (11.9 months) and CCI = 1 (8.4 months; P < .001). Comorbidity and advancing age in as little as 5-year increments are important adverse factors in this group. Most patients died of lymphoma within a year from diagnosis, underscoring the importance of developing new treatments.