Background: Spices especially in form of herbs and leaves, are commonly used in food preparation in eastern Nigeria. However, they are not usually accounted for in the nutritional content of foods. Byrsocarpus dinklagei is one of the uncommon aromatic spices added to cooked food for enhanced organolpetic properties and health purposes. Objective: This study evaluated the proximate, vitamins and phytochemical compositions of B. dinklagei (efu) spice. Methods: Seeds of B. dinklagei were dried in a cabinet dryer at 70oC to a constant weight and pulverized to powder. The ground powder was evaluated for proximate, vitamins and phytochemical compositions using standard methods. Data obtained was analyzed for mean and standard deviation. Results: The results showed that the spice contained 4.14% protein, 20.54% moisture, 2.19% fat, 1.83% ash, 1.94% crude fiber and 74.71% carbohydrate. Byrsocarpus dinklagei seeds powder contained 19.60 mg/100g of vitamin B2, 9.09 mg/100g vitamin C and 1.60 mg/100g of beta carotene. The mineral contents per 100g were 3.3mg Mg, 14.10 mg K, 0.9mg Na, 1.0 mg Ca, 212.0mg Mn, 598.0 mg Fe, 72 mg Cu and 144.0 mg Zn. The identified phytochemical content of B. dinklagei were 8.50 mg/100g of tannin, 115.10 mg/100g of alkaloid, 57.60 mg/100g of flavonoid, 21.00 mg/100g of saponin, 41.1 mg/100g of phytate and 25.00 mg/100g. Terpene profilr showed the presence of alpha-pinene, beta-myrcene, delta 3-carene, limonene, and rho-cymene as the main terpenes detected in the spice with a total terpene content of 50.70 mg/100g. Conclusion: The spice powder is a rich source of micronutrients and phytochemicals of biological significance.