Introduction: preclinical research studies of Jatropha curcas L. (piñón blanco) root extract proved its antidiarrheal activity; however the chronic toxicity test of the total seed extract demonstrated diarrheal effect. Objectives: to determine the effect of the alkaloid extract from Jatropha curcas L. seeds on the gastrointestinal motility. Methods: fifty albino mice with average weight of 25 g were used. The Arbos et al. ́s method was applied. The intestinal marker was 5 % activated charcoal administered at a dose of 0.1 mL/10 g. The experimental groups included 0.1 mL/10 g of distilled water, 1.5 mg/kg of atropine, alkaloid extract of Jatropha curcas L. seeds at doses of 500 and 1 000 mg/kg respectively, and 1 g/kg of neostigmine The statistical validation was based on Kruskal-Wallis test, ANOVA, and Tukey and Newman-Keuls test. Results: the percentages of the charcoal run were 69.21, 36.37, 58.96, 49.65, and 74.17 respectively. The ANOVA test demonstrated statistical significance (p< 0.05, IC 95 %). Comparative Tukey and Newman-Keuls test showed statistical significance between distilled water and Jatropha curcas at a dose of 1 000 mg/kg. Conclusions: the decrease on the gastrointestinal motility resulting from the effect of the alkaloid extract of Jatropha curcas seeds was proved at a dose of 1 000 mg/kg.