BACKGROUND: Some genetically characterized patients show the rapid disease progression during immune checkpoint inhibitors (ICIs) monotherapy, a phenomenon known as hyperprogressive disease (HPD). CASE PRESENTATION: Herein we report a relevant case of biliary tract cancer (BTC) that initially responded to gemcitabine plus oxaliplatin (GEMOX) and PD-1 blockade but subsequently developed HPD in the process of PD-1 blockade maintenance therapy, leading to death within two weeks. Genomic analysis revealed mutations in CDKN2A, PIK3CA, KRAS and EPHA2 in both baseline and hyperprogressive plasma and tumor samples. Notably, higher KRAS mutation abundance was observed in plasma and ascites after disease progression. CONCLUSIONS: These findings suggest a potential association between these negative genes especially KRAS mutation and HPD. Therefore, administration of PD-1 blockade monotherapy in this subgroup of patients harboring KRAS mutation should be performed with caution. Further studies are warranted to confirm these results and explore the correlation between genomic mutations and HPD.