2-Aryl-3-bromoquinolin-4(1H)-ones and 2-aryl-3-bromo-1-methylquinolin-4(1H)-one were evaluated for their antiangiogenic effects. Results showed that the 2-aryl-3-bromoquinolin-4(1H)-ones (QNHFBr and QNHClBr), and the 3-bromo-2-(4-chlorophenyl)-1-methylquinolin-4(1H)-one (QNMeClBr) reduced endothelial cell numbers in an assay of cell proliferation, showing increased cytotoxicity at higher doses. The compounds also inhibited neovessel growth in an ex vivo assay of angiogenesis. Furthermore, low levels of proangiogenic factors, namely, basic fibroblast growth factor (bFGF) and vascular endothelial growth factor/placental growth factor (VEGF/PlGF) were obtained in cultures treated with these compounds. Thus, the tested compounds, QNHFBr, QNHClBr, and QNMeClBr exhibit antiangiogenic activity.