Using radioimmunoassay technique, levels of leukotriene B4 and C4 (LTB4 and LTC4) in the aqueous humor of rabbit eyes were measured following experimental nonpenetrating ocular trauma. Slit lamp examination showed a time-dependent increase of flare, cells, and fibrin in the anterior chamber of the traumatized eyes. Polymorphonuclear (PMN) leukocyte influx into the aqueous humor was not seen at 6 hours but increased significantly in traumatized eyes after 12 hours. No inflammatory cells were observed in control eyes. Histopathologic studies demonstrated injuries of the ciliary body, ruptures of the retina and choroid, with intraocular hemorrhage. LTB4 values peaked at 6 hours, prior to PMN cell infiltration and remained significantly higher than controls, which remained undetectable at all intervals after injury. LTC4 values also peaked by 6 hours in the traumatized eyes. These data demonstrate that elevations in LTB4 and LTC4 are associated with blunt trauma, and this precedes PMN cell infiltration. Leukotrienes may play a role in the early inflammatory response following concussive ocular injuries.