Hypoxia (low O2) is a pathobiological hallmark of solid cancers, resulting from the imbalance between cellular O2 consumption and availability. Hypoxic cancer cells (CCs) stimulate blood vessel sprouting (angiogenesis), aimed at restoring O2 delivery to the expanding tumor masses through the activation of a transcriptional program mediated by hypoxia-inducible factors (HIFs). Here, we review recent data suggesting that the efficacy of antiangiogenic (AA) therapies is limited in some circumstances by HIF-dependent compensatory responses to increased intratumoral hypoxia. In lieu of this evidence, we discuss the potential of targeting HIFs as a strategy to overcome these instances of AA therapy resistance.