The rising prevalence of allergic diseases, driven by environmental and genetic factors, underscores the need for alternative therapeutic strategies with fewer side effects. Plant-derived compounds offer promising potential in allergy management due to their natural origin and bioactivity. This chapter outlines a methodological framework for the extraction, characterization, and preliminary evaluation of anti-allergic compounds from plant leaves. Fresh leaves are collected, shade-dried, powdered, and subjected to ethanol-based crude extraction. To enhance yield and purity, fractionation is carried out through liquid-liquid partitioning followed by soxhlet extraction. The obtained phytochemicals are analyzed using techniques such as thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and gas chromatography–mass spectrometry (GC–MS) to identify major bioactive constituents like flavonoids, alkaloids, and phenolics. Preliminary screening methods, including skin prick and patch tests, are discussed for assessing anti-allergic activity. The protocol described serves as a foundational guide for researchers aiming to explore plant-based approaches in allergy research and drug development.