ObjectiveTo develop and validate a nomogram for predicting the cancer-specific survival in patients with intrahepatic cholangiocarcinoma (ICC) after hepatectomy. MethodsSuitable patient cases were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Nomograms were established based on the independent prognostic factors identified by COX and Lasso regression models. The performance of the nomograms was validated internally and externally by using the concordance index (c-index), calibration plot, and decision curve analysis. ResultsThe multi factor COX regression results showed that: age, gender, T stage, tumor grade, tumour diameter and number of positive lymph nodes were independent prognostic predictors for cancer-specific survival (CSS) in ICC patients. Nomogram predicting CSS had a c-index of 0.66 (95%CI 0.64 to 0.69) in the training cohort and 0.67 (95%CI 0.63 to 0.72) in the internal validation cohort. The 1-, 3- and 5-year areas under the curve (AUC) of nomogram were 0.68, 0.74 and 0.75 in the training cohort respectively. In the validation cohort, the 1-, 3- and 5-year AUC of nomogram were 0.69, 0.68 and 0.71, respectively. ConclusionThe prediction model constructed based on six factors, including age, gender, pathological stage, T-stage, tumour diameter and number of positive lymph nodes, shows good prediction accuracy.