The present invention relates to methods of use of RNAi agents, e.g., double stranded RNAi agents, targeting a Factor XII (Hageman Factor (F12) gene, for treating subjects having a contact activation pathway-associated disease, such as a thrombophilia or hereditary angioedema (HAE), methods for preventing at least one symptom in a subject having a contact activation pathway-associated disease, such as a thrombus formation or an angioedema attack, and RNAi agents targeting an F12 gene, for use in the methods of the invention.