Garlic (Allium sativum) is an important flavouring component in Indian cuisine. Allicin, a sulphur containing compound, is the most abundant component of garlic and has been widely studied for its antimicrobial and antioxidant properties. It is also known to play a role in the regulation of blood pressure and cholesterol levels. Despite the known health benefits associated with allicin, systematic studies on its anti-cancer properties using animal models are very limited. This study aimed to develop a simple method for the extraction of allicin from fresh garlic, study the stability of the extracted compound at various temperatures, and evaluate the antioxidant, anti-proliferative, pro-apoptotic and anti-angiogenic properties in zebrafish. A five-month stability study indicated that allicin remains significantly stable at temperatures 4 °C and below but shows extensive degradation if stored at room temperature. The in vivo studies in zebrafish using a combination of mutants and transgenic lines demonstrated the antioxidant, anti-proliferative, apoptotic and anti-angiogenic properties of allicin. The study highlights the importance of natural bioactive compounds as potential anti-cancer agents that can be studied further.