The present disclosure relates to RNAi agents useful in methods of treating KRAS-related diseases such as a proliferative disease, including without limitation a solid or liquid cancer, adenocarcinoma, colorectal cancer, advanced and/or metastatic colorectal cancer, colon cancer, lung, non-small cell lung cancer and lung adenocarcinoma, acute myelogenous lung, bladder, brain, breast, cervical, endometrial, gastric, head and neck, kidney, leukemia, myelodysplastic syndrome, myeloid leukemia, liver, melanoma, ovarian, pancreatic, prostate, testicular, thyroid cancers, and cardio-facio-cutaneous (CFC) syndrome and Noonan syndrome, and similar and related diseases, using a therapeutically effective amount of a RNAi agent to KRAS.