Bat guano is widely used in oasis basins in the Zinder region. However, no study has been conducted to determine its chemical components of this product. The objective of this present study is the physicochemical characterization of Magarawa's guano. Bat guano samples were collected from the caves of Magarawa mound and submitted for different analysis. After preparation and packaging, the samples were observed under a microscope (x10) then subjected to chemical analyzes of elements such as nitrogen, phosphorus, potassium, bases and also lipids, proteins and carbohydrates. It emerges from this study that bat guano from Magarawa occurs in small sticks 2 mm in length and very friable in the dry state with the presence of fragments of insect remains and skeleton of bats or snakes or birds. It has a high nitrogen content (10%) and low phosphorus and potassium concentrations. The concentration of dry matter and protein remains high 92.5 and 60.66% respectively. Indeed, the physico-chemical characteristics of Magarawa's guano show that this product is a good quality organic fertilizer that is easy to handle and above all competitive compared to commercial guanos.