Previous studies have shown meconium-induced lung injury occurs throughout release of inflammatory cytokines. The exact mechanism of cytokine-induced apoptosis is not known. In this study we hypothesized that meconium-induced apoptosis in the lungs is mediated through the production of inducible nitric oxide (NO). We studied two groups of newborn rabbit pups: one group was instilled with meconium and other with normal saline. We measured precursors of NO in lung lavage from both groups of rabbits and NO levels were calculated accordingly. The levels of NO and NO-derivatives increased significantly in both groups. However NO expression in meconium group 2 h after meconium instillation was significantly higher than in saline-instilled group suggesting NO production plays a role in meconium-induced inflammation.