Objective To explore the CT and MRI imaging and clinicopathological features of extranodal NK/T cell lymphoma (NK/TCL). Methods Sixty-six patients with NK/TCL diagnosed from 2002 June to 2016 April in Beijing Tongren Hospital with intact CT and/or MRI imaging results were enrolled in this study. All the patients had tailed clinical information and follow-up. The imaging and clinicopathological features were analyzed retrospectively and their prognostic value on overall survival was analyzed. Results There were 49 males and 17 females with median age of 42 years. The median follow-up time was 18 months. The cases showed surrounding invasions including 10 cases (15.2 %) in soft palate, 5 cases (7.6 %) in hard palate, 2 cases(3.0 %) in tonsil, 8 cases(12.1 %) in upper lip, 13 cases(19.7 %) in maxillofacial soft tissue, 9 cases (13.6 %) in eyelid, 10 cases (15.2 %) in orbital, 3 cases (4.5 %) in maxilla, 6 cases (9.1 %) in pterygopalatine fossa,6 cases(9.1 %)in infratemporal fossa,3 cases(4.5 %)in skull base, 3 cases(4.5 %) in eyeball and 2 cases (3.0 %) in brain tissue. Kaplan-Meier survival analysis found that the 2-year overall survival rates of the patients with the involvement of hard palate, upper lip, maxillofacial soft tissue, eyelid, orbital, maxillary, eyeball and brain organizer were lower than those of the patients without the involvement of these sites(χ2values were 4.470,4.041,4.456,13.933,8.986,4.000,44.121,6.527,16.822,respectively, all P< 0.05). Further multivariate Cox regression analysis showed that maxilla and brain involvement were independent adverse factors (RR=34.717, 95 % CI 3.404-354.035, P=0.003; RR=37.545, 95 % CI 3.188-442.187, P= 0.004). Conclusions MRI and CT examinations are of great value in diagnosis and prognostic assessment of NK/TCL. Clinicians can make correct and timely diagnosis by comprehensive clinical, radiological and pathological features and can make a detailed clinical assessment to give patients appropriate treatment,thus improving the outcome of the NK/TCL patients.