Primary gastrointestinal natural killer (NK)/T-cell lymphoma (PGINKTL) is a rare T-/NK-cell lymphoma subtype, and the clinical features and survival outcomes remain largely unknown.To summarize the clinical features and survival outcomes of PGINKTL, PGINKTL cases diagnosed at our hospital from May 1999 to December 2020 were reviewed; and the clinical data, information on treatment strategies, and survival were collected. Survival analysis was performed using the Kaplan-Meier method and multivariable Cox proportional hazards regression. We constructed a nomogram to visualize the survival prediction of PGINKTL. The discriminative ability and calibration of the nomogram for prediction were tested using the concordance index (C-index) and calibration plots.The cohort included 81 cases, the median age was 36 years (range, 7-80 years), and the male-to-female ratio was 1.7:1. The most common clinical symptom at the time of diagnosis was abdominal pain (71.6%). The most common lesion site was the colon (59.3%). During a median follow-up period of 37.7 months, the median overall survival (OS) time of 81 patients was 4.0 months (95% confidence interval [CI], 3.1-4.9 months), and the 2-year OS rate was 30.7% (95% CI, 20.3%-40.1%). The multivariate analyses indicated that patients with an Eastern Cooperative Oncology Group (ECOG) performance status (PS) score ≥2, serum lactic dehydrogenase (LDH) level ≥ the upper limit normal (ULN), and perforation had worse OS. We used these data to establish a nomogram to predict survival for PGINKTL. The nomogram displayed good accuracy, with a C-index of 0.726.The clinical features and poor outcomes of PGINKTL, which is a rare and fatal lymphoma type, are presented. The proposed nomogram provides an individualized estimate of survival for these patients. In the future, the study focused on exploring a better treatment strategy to improve survival is required in PGINKTL.© 2022 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.