Proximate composition and cholesterol content, fatty acid and amino acid profiles, selected mineral (Na, K, Mg, Ca, P, Fe, Zn, Cu) and vitamin (thiamin, riboflavin, niacin, pyridoxine, vitamin B12) content, total and soluble collagen content, and purine bases (adenine, guanine, xanthine, hypoxanthine) were determined in composite samples prepared from raw horse thigh muscles. Mean content (per 100 g edible portion) of protein, lipid, ash, and cholesterol was 19.8 g, 6.63 g, 0.98 g, and 61 mg, respectively. Saturated, monounsaturated, and polyunsaturated fatty acid contents were 34.8, 46.5, and 18.6% of total fatty acid methyl esters, respectively, with 100 g flesh providing 1.97, 0.68, and 0.32 g of oleic, linoleic, and α-linolenic acid, respectively. Compared to human requirements, horsemeat protein was high in lysine and threonine (1.57 and 0.84 g/100 g edible portion, respectively), but low in tryptophan (0.15 g). Compared to other meats, horsemeat proved to be a valuable source of P, Fe, Zn, Cu, and Mg (231, 3.89, 3.72, 0.20, and 28.9 mg/100 g edible portion, respectively), providing approximately 29, 28, 25, up to 13, and 10% RDA, respectively. Vitamin B12(2.08 μg/100 g edible portion), pyridoxine (0.64 mg/100 g), and niacin (5.54 mg/100 g) met 208, 32, and 31% RDA, respectively. Total collagen content was 1.17 g/100 g edible portion, 10% of which was soluble. Adenine, guanine, xanthine, and hypoxanthine mean levels were 18.3, 8.23, 9.01, and 74.0 mg/100 g edible portion, respectively.