Olaparib is an oral poly ADP-ribose polymerase inhibitor with activity in germline BRCA1 and BRCA2 (BRCA1/2)-associated breast and ovarian cancers. There is no report about treatment with olaparib in BRCA1/2-mutated intrahepatic cholangiocarcinomas. This study is to observe the efficacy and safety of olaparib monotherapy in the refractory BRCA1/2-mutant intrahepatic cholangiocarcinoma (ICC) patient. The clinical record of a patient with BRCA2-mutated refractory advanced ICC treated with olaparib was analyzed. The patient was administered with olaparib (400 mg orally twice daily) and followed up for 11 months. The clinical tumor response was evaluated after 4 weeks of olaparib treatment, and then every 8 weeks (two treatment cycles). The patient achieved partial response confirmed by the computed tomography and the tumor marker CA19.9, CA50, and CA125 levels decreased significantly as an outcome of the treatment. The quality of life improved significantly. Major adverse events were fatigue, thrombocytopenia, leukopenia, and anemia, which were manageable with medication. The patient is still receiving treatment. Olaparib in the treatment of BRCA2-mutation-associated refractory advanced ICC patent is effective, and the adverse effects are tolerated. Large-scale studies should be conducted to further the adoption of genomic profiling, which may help clinicians identify suitable biomarkers for therapy of ICCs. A possible line of therapy is often extrapolated from case reports or small case series.