ABSTRACT This experiment was carried out to determine the effects of using garlic extract (Allium sativum) as an alternative to formaldehyde for the disinfection of hatching eggs on hatching traits and growth performance of quails. Four treatments, with 240 hatching eggs each, were evaluated: egg immersion in two different levels (2.5% and 5.0%) of garlic extract (garlic-1, garlic-2), formaldehyde fumigation (positive control), and eggs not submitted to disinfection (negative control). Mid-term and late embryomortality, pipped egg, and culled chick rates were not influenced by the (p>0.05). The highest (p<0.05) early embryo mortality rate was detected in the formaldehyde treatment (9.99%), and the lowest in garlic-2 treatment (2.68%). Hatchability of fertile eggs was the lowest in the formaldehyde group (83.78%), followed by the control (85.20%), garlic-1 (87.11%) and garlic-2 (88.72%) groups, respectively. The highest final body weight (5 weeks of age) was obtained in the garlic-2 group (304.1 g), followed by the control (294.13 g), formaldehyde (290.56 g), and garlic-1 (288.44 g), respectively, and the differences were statistically significant (p<0.05). Feed intake and feed conversion ratio were not influenced by the treatments (p>0.05). The results obtained for hatching traits and live performance parameters indicated that the immersion of eggs in garlic extract may be used as an alternative to formaldehyde fumigation for the disinfection of hatching quail eggs.