Animals are slaughtered to produce their by-products which can be well utilized for variousrnapplications in day to day human life, thus, contributing to the value of animals. Understandingrnits chemical composition as well as its stability is very important for its proper utilization andrnalso for its technological application. The Black Head Somali Sheep's tail-fat, obtained fromrnpasture sites (Borena & Gode) consisting of three sheep each, and non pasture sites ( Alfoz andrncooperate) also consisting of three sheep each, were collected in Ethiopia from different actualrnfeeding areas comprising of a total of twelve (n=12) intact male sheep were investigated. Inrnaddition to the fat content of the sheep tail, the fatty acid composition and oxidative stability ofrnthe tail-fat were determined by GC-MS and professional rancimat method respectively and thernquality control parameters including peroxide value, acid value, saponification value, moisturerncontent and refractive index were evaluated. The fat content of tail tissue from Borena (B) siternamounted 75.50%, whereas that of Gode, Alfoz (AF) and Cooperate(C) were found to be 78.50,rn73.66 and 75.48%, respectively. The determined fatty acids composition of sheep tail-fat wererncomprising of a number of fatty acids which involves Myristc acid (C14:0), palmitic acid, stearicrnacid (C18:0), oleic acid (C18:1), Elaidic acid (C18:1n-9t), linoleic acid (C18:2),linolenic acidrn(C18:3). The oxidative stability of the oils, as measured by the Rancimat test at 110OC andrn120OC, and extrapolated to real shelf life of tail- fat were 1.67yr,1.58yr,2.01yr and 1.92yr for thernsheep's tail- fat obtained from B, G, AF & C sites respectively. In conclusion, there arerndifferences between study group for the their fatty acids composition. The sheep tail fat fromrnPasture sites had better attributes of fatty acid composition with higher PUFA, UFA/SFA ratio,rnEFA and total n-3 PUFA. Also sheep tail fat from Pasture sites have lower oxidative stabilityrnand lower initial quality in terms of its PV and AV in general terms due to its fatty acidrncomposition compared to non pasture sites.