RNA interference (RNAi) triggers and RNAi trigger conjugates for inhibiting the expression of Hif2α (EPAS1) gene are described. Pharmaceutical compositions comprising one or more Hif2α RNAi triggers optionally with one or more additional therapeutics are also described. Delivery of the described Hif2α RNAi triggers to tumor cells in vivo provides for inhibition of Hif2α gene expression and treatment of cancer.