The present invention relates to RNAi agents e.g. double stranded RNAi agents targeting the Kallikrein B Plasma (Fletcher Factor) 1 (KLKB1) gene the Factor XII (Hageman Factor (F12) gene or the Kininogen 1 (KNG1) gene and methods of using such RNAi agents to inhibit expression of a KLKB1 gene an F12 gene and/or a KNG1 gene and methods of treating subjects having an hereditary angioedema (HAE) and/or a contact activation pathway associated disorder.