Filariasis is a vector-transmitted parasitic disease caused by Filarioidea nematode with world wide spread especially in tropical and sub-tropical countries. This is highly prevalent in hot and humid areas of India mainly hilly parts of India like Tarai region of Uttar Pradesh and coastal areas of Andhra Pradesh. The tentative diagnosis was carried out by direct faecal smear examinations, wet blood film observation and blood smear examinations, and modified Knott’s technique, further case history was reviewed. The collected blood was subjected to different staining techniques including modified Knott’s technique. On modified Knott’s method examination detected microfilaria is long slender anterior blunt and tapering posterior ends. Ivermectin 200 μg/kg body weight subcutaneous route (orally microfilaricide 50 ug/ kg) is used as a curative drug in present clinical case and animal was responded well with the treatment. Hematological parameters of buffalo includes decreased hemoglobin (6.5 grs /dl), packed cell volume (20%), and total erythrocytic count (4.5×106/ul) were recovered within 1 week after treatment.