Airway smooth muscle (ASM)-cell hyperplasia is a cardinal feature of the remodeled airways in asthma and contributes to airway hyper-responsiveness. Several upregulated mediators are potentially involved in this architectural change. Recently, many investigators have turned their interest toward fibroblast growth factor (FGF)2. This opinion article describes the current knowledge on the biology of this growth factor, reviews the papers that have measured its baseline or allergen-induced expression in human asthmatics and summarizes observations supporting its role as an ASM cell mitogen. The possibility that FGF2 is involved in ASM-cell hyperplasia is raised, not only because it induces ASM-cell proliferation by itself but because of recent findings showing that FGF2 confers to ASM cells the ability to proliferate in response to different asthma mediators.