The banana pseudostem and rhizome which are considered to be of little or no importance is often discarded as waste after the fruit is being harvested, thereby constituting a menace to the environment. This study was therefore designed to determine the nutritional compositionsand antioxidant activities (AA) of banana (Musa sp.) pseudostem (BP) and rhizome (BR) as possible sources of nutrients in formulating food for human and animal feeds. Samples were collected from Amogera district, Gurage Zone of Southern Ethiopia. The determinations were done using standard methods of analyses of Association Official Analytical Chemists (AOAC), Atomic Absorption Spectrophotometric (FAAS) for the proximate and minerals respectively. Total phenolic content (TPC), and total flavonoid content (TFC) of the extracts were determined by using Folin-ciocalteau and AlCl3 methods respectively, and the AA was determined by using 2, 2-diphenyl- 1-picrylhydrazyl (DPPH) assay. A 0.50 g an oven-dried sample was wet-digested using 3 mL of (69 - 72%) HNO3 and 3 mL of (70%) HClO4, for 2 h at 270 OC. The validity of the optimized procedure

was evaluated by the analysis of spiked samples whose recovery was in the range of 94 - 99%. The mean proximate composition ranges were recorded in BP and BR (%), respectively moisture (7.5 - 10.97), ash (8.23 - 9.03), crude protein (0.88 - 0.33), crude fat (1.8 - 2.66), crude fiber (6.12 - 10.12) carbohydrate (64.69 - 74.64). The mean mineral contents ranges (mg/kg), Ca (61.84 - 58.75), Cd (0.0183 - 0.018), Zn (59.60 - 56.92). The concentration of Ni, Cr and Pb metals in BP and BR samples were below the detection limit. The concentration of Ca was the highest in both BP and BR. Among the trace elements, Zn was found to be the highest. The methanol extract of BR showed higher TPC and TFC (560.2 mg GAE/g and 405.12 mg QRE/g of extract respectively) and methanol extract of BR showed the highest DPPH radical scavenging activity (IC50 = 58.9 μg/mL). BP and BR can be sources of nutrients in food, animal feed nutraceuticals preparation, as they are high in carbohydrate, fiber,essential mineral contents and antioxidants. This will result in proper banana wastes utilization and help in solid waste management, thereby sustaining the environment.