Giardiasis, caused by the parasite Giardia lamblia, is a prevalent and serious public health concern, particularly affecting children worldwide. The primary mode of transmission for the parasite is through contaminated food and water sources and often leads to the onset of diarrhoea in infected individuals. However, the present medications for Giardiasis treatment often come with numerous side effects, while the growing problem of drug resistance adds a significant complication. Therefore, there is an urgent need for alternative treatments. In this study, we explored the in-vitro potential of Andrographis paniculata leaf extract as a possible alternative treatment for Giardiasis. Our investigation involved assessing the impact of the ethanolic extract on Giardia trophozoites through the analysis of parameters such as cell death, morphological alterations, adherence, ROS generation, and cell cycle dynamics. A. paniculata leaf extracts demonstrated significant inhibitory activity against the growth of Giardia trophozoites. After being incubated for 24 hours, the test results revealed an IC50 value of 51.26µg/ml (95% CI 37.17- 65.35) for inducing cell death in Giardia trophozoites. We observed a substantial degradation of DNA, alteration in morphology, inhibition in adherence, ROS generation and inhibition of the cell cycle in Giardia trophozoites. The findings indicate that A. paniculata extract has the potential to be used as a therapeutic treatment for giardiasis. This approach aims to offer a natural therapeutic solution for giardiasis, minimizing side effects and reducing the risk of drug resistance.