Introduction: Azadirachta indica A. Juss, popularly known as neem, has been gaining ground in alternative herbal medicine. This plant offers a constant source of new and unique phytochemicals that are used in the development of new drugs. Aim: A preliminary chemical analysis was carried out to detect secondary metabolites present in the crude hydroethanolic extract of dried and macerated leaves of A. indica and to evaluate its antioxidant and toxic potential. Methodology: The chemical analysis, which was performed according to a procedure described in the literature, identified data positive for phenols, tannins, leucoanthocyanidins, catechins, flavones, flavonoids and xanthones, and the absence of anthocyanins, anthocyanidins, chalcones, aurones, flavonols and flavanones. Results: The quantitative test by the DPPH method, performed in an ultraviolet-visible spectrophotometer, revealed moderate at the highest concentration of 250.0 μg.mL-1. An investigation of the toxicity potential of the crude extract against larvae of Artemia salina Leach, indicated LC50 = 596.7 μg.mL-1, placing it within the range of moderate toxicity when compared to data in the literature. Conclusion: These studies therefore indicate that crude hydroethanolic extract of A. indica leaves contains substances with medicinal properties and that it is safe for therapeutic purposes.