Secondhand smoke exposure alters arachidonic acid (AA) metabolism in cystic fibrosis (CF) macrophages. Lipidomics for AA metabolites was performed via high-performance liquid chromatography-tandem mass spectrometry in CF and non-CF macrophage supernatants from children and adults after exposure to either 0% or 15% cigarette smoke extract (CSE), n=3, 24 hours challenge. *p<0.05, t-test. LTE4, leukotriene E4; LXA4, lipoxin A4; PGE2, prostaglandin E2; PGD2, prostaglandin D2; 8(S)-HETE, 8S-hydroxy-5Z,9E,11Z,14Z-eicosatetraenoic acid; (9(S)-HETE, 9S-hydroxy-5Z,7E,11Z,14Z-eicosatetraenoic acid; 12(S)-HETE, 12(S)-hydroperoxy tetraenoic eicosatetraenoic acid.