Objective: Determine the content of total phenols and evaluate the gastroprotective effect of the extract of Persea caerulea (Ruiz & Pav.) Mez. in mice with induced gastric ulcer. Material and Methods: The bark of Persea caerulea was macerated in 70% ethanol and the phenol content was determined using the Folin-Ciocalteu method. The female Mus musculus Balb/c specimens were distributed in the following groups: White Control Group, without indomethacin dosing; Negative Control Group, dosing with indomethacin; Positive Control Group treated with ranitidine at a dose of 50 mg/kg; Groups P. caerulea treated with extract at doses of 50 mg/kg, 100 mg/kg and 200 mg/kg. Gastric ulcer was induced with indomethacin orally at a dose of 50 mg/kg, the procedure was repeated 12 hours later; Gastroprotective treatment was administered 60 minutes after each dose of indomethacin, 6 hours after the last dose, sodium pentobarbital was euthanized and the stomach was resected to determine ulceration using the Marhuenda Scale. Results: Higher percentages of gastric ulcer inhibition were obtained in the P. caerulea 100 mg/kg (80%) and P. caerulea 200 mg/kg (85.71%) groups. Conclusions: Extract of Persea caerulea (Ruiz & Pav.) Mez., At doses of 100 and 200 mg/kg of body weight, has a gastric antiulcerative effect which is related to its content of total polyphenols.