A swallow-tailed perylene derivative including a triphenylphosphine moiety was synthesized and applied to the detection and the live-cell imaging of lipid hydroperoxides. The novel probe, named Spy-LHP, reacted rapidly and quantitatively with lipid hydroperoxides to form the corresponding oxide, Spy-LHPOx, which emits extremely strong fluorescence (Phi approximately 1) in the visible range (lambda(em) = 535 nm, 574 nm). Spy-LHP was highly selective for lipid hydroperoxides, and the addition of other reactive oxygen species (ROS) including hydrogen peroxides, hydroxyl radical, superoxide anion, nitric oxide, peroxynitrite, and alkylperoxyl radical, caused no significant increase in the fluorescence intensity. The probe exhibited good localization to cellular membranes and was successfully applied to the confocal laser scanning microscopy (CLSM) imaging of lipid hydroperoxides in live J774A.1 cells, in which lipid peroxidation was proceeded by the stimulation of 2,2-azobis(2-amidinopropane)dihydrochloride (AAPH). These findings establish Spy-LHP as a promising new tool for investigating the physiology of lipid hydroperoxides.