Aberrant activation of Wnt signaling contributes to ischemia-induced retinal neovascularization in oxygen-induced retinopathy (OIR), although the underlying mechanism is so far unclear. Here, we show that microRNA-184 (miR-184) is significantly down-regulated in the retina of OIR mice, and miR-184 negatively modulates Wnt signaling both in vivo and in vitro. Furthermore, we show that the Wnt receptor, frizzled-7, is a downstream target of miR-184, and delivery of miR-184 mimic inhibits Wnt signaling in the OIR retina. These results suggest that decreased levels of miR-184 are responsible, at least in part, for the aberrant activation of Wnt signaling in ischemia-induced retinal neovascularization.