Diagnosis plays a crucial role in understanding disease manifestation in parasitology, as parasites often produce diverse and overlapping clinical features. Accurate diagnostic tools help in identifying the causative parasite, assessing disease severity, monitoring progression, and guiding appropriate treatment. These tools can be broadly categorized into clinical, microscopic, immunological, molecular, imaging, and biochemical methods, each contributing uniquely to disease detection and interpretation. Clinical diagnosis is the initial step and is based on patient history, symptoms, travel history, exposure risks, and physical examination. Manifestations such as anemia, fever, diarrhea, hepatosplenomegaly, skin lesions, or neurological signs often provide clues toward parasitic infections. However, clinical features alone are rarely sufficient due to non-specific symptoms shared with other diseases. Microscopic examination remains the cornerstone of parasitological diagnosis. Direct demonstration of parasites, their eggs, cysts, trophozoites, or larvae in clinical samples such as stool, blood, urine, sputum, or tissue biopsies confirms infection. Techniques include wet mount preparation, concentration methods, staining techniques like Giemsa stain for blood parasites, and modified acid-fast staining for coccidian parasites. Blood smear examination is essential for diseases such as malaria and filariasis, where parasite morphology