SummaryPeripheral T‐cell lymphomas (PTCLs) are a heterogeneous group of haematological cancers with generally poor clinical outcomes. However, a subset of patients experience durable disease control, and little is known regarding long‐term outcomes. The International T‐cell Lymphoma Project (ITCLP) is the largest prospectively collected cohort of patients with PTCLs, providing insight into clinical outcomes at academic medical centres globally. We performed a long‐term outcome analysis on patients from the ITCLP with available 10‐year follow‐up data (n = 735). The overall response rate to first‐line therapy was 68%, while 5‐ and 10‐year overall survival estimates were 49% and 40% respectively. Most deaths occurred prior to 5 years, and for patients alive at 5 years, the chance of surviving to 10 years was 84%. However, lymphoma remained the leading cause of death in the 5‐ to 10‐year period (67%). Low‐risk International Prognostic Index and Prognostic Index for T‐cell lymphoma scores both identified patients with improved survival, while in multivariate analysis, age >60 years and Eastern Cooperative Oncology Group performance status 2–4 were associated with inferior outcomes. The favourable survival seen in patients achieving durable initial disease control emphasizes the unmet need for optimal front‐line therapeutic approaches in PTCLs.