The roots of Ligusticum porteri J.M. Coult. & Rose, Apiaceae, are used in Mexican traditional medicine for the treatment of gastrointestinal disorders. The dimeric phthalide (Z´)-diligustilide found in their organic extracts is associated with the gastroprotective properties. In this study, the gastroprotective effect of nanoemulsion of the volatile oil from the roots of L. porteri (at doses of 1, 3, 10, and 30 mg/kg) in the indomethacin-induced gastric damage model was tested, and nitric oxide (NO) and hydrogen sulfide (H 2 S) gastric levels were determinate. The volatile oil obtained by steam distillation (0.63% yield) contained 37 constituents, as assessed by GC-MS analysis, where the significant compounds were 4-phenyl-3-buten-2-ol (20.54%) and (Z)-3-butylidenephthalide (20.54%) that correspond to phthalide monomers. These results demonstrate that nanoemulsion of the volatile oil from L. porteri (at 10 and 30 mg/kg) shows a significant gastroprotective effect (72 and 92% respectively) against indomethacin-induced gastric damage, which is not different from the gastroprotective effect of omeprazole (69%) (p < 0.05). Furthermore, these doses of the nanoemulsion maintain the basal H 2 S gastric levels (209.70 ± 11.50 and 222.0 ± 5.30 nmol/g tissue) even in the presence of indomethacin. From these findings, we concluded that L. porteri volatile oil in nanoemulsion preparation might facilitate the gastroprotective action and it could serve as a future therapeutic approach for NSAID-related gastropathy.