The antigens used in vaccines are usually attenuated or inactivated microorganisms, toxoids or purified particles. The purified particles have a better biosecurity but their capacity to generate an immune response is low, therefore vaccines include adjuvants that seek to improve immunogenicity. Unfortunately, adjuvants have side effects so only aluminum salts are currently used as adjuvants. So that this work evaluated an adjuvant of garlic extracts, a plant with immunomodulatory properties, in mice immunized with ovalbumin. To formulate the adjuvant, biotoxicity and cytotoxicity assays with a model of Artemia salina and haemolytic activity were considered respectively. A qualitative phytochemical analysis and quantification of phenolic compounds were carried out and in the immunization scheme 100 μg of antigen with adjuvant were administered at day 1, 50 and 100 μg of antigen on days 14 and 28 respectively. The sacrifice of the animals was done on day 30. Leukocytes and γ globulins were quantified at the beginning and at the end of the experiment. A lethal dose 50% of 1430 μg/mL was calculated for the Garlic extracts, a haemolytic activity of 2.66% and 7.53% was observed (p<0.05) for the concentrations of 10 and 100 μg/mL. And it was only possible to identify the presence of tannins in the aqueous extract of Garlic. With the results obtained, significant differences were observed in leukocyte counts and concentration of γ globulins at the end of the immunization scheme (p<0.05). Concluding that the results with the adjuvant of Garlic at 10 μg/mL concentration were comparable to those found with the adjuvant of aluminum salts.