This study was conducted to optimize the compositions of amaranths, teff and barley flour blending ratios for better nutritional and sensory acceptability of injera. Ten formulations of composite flour were determined using D-optimal constrained mixture design with the aid of MINITAB17 software package. The ingredients were in the range of 40-100%, 0-60% and 0-20% for teff, amaranths and barley, respectively. Proximate and mineral analysis of injera was done using standard methods, and sensory evaluation was made using 5-point hedonic scales. Results of the study showed a significant difference (p < 0.05) in protein, calorie, fiber, calcium, iron, zinc and sensory quality of injera as the compositions of ingredients were changed. Levels of protein and gross energy increased with the increased proportion of amaranths, and addition of barley increased the carbohydrate value of injera. Calcium, iron and zinc contents of injera increased with the increment of amaranths and teff. Overall optimum point protein (11.84-14.60%), carbohydrate (74.39-79.71%), gross energy (363.68-381.22 kcal/100 g, iron ABOUT THE AUTHORS Fitsum Woldemariam graduated from department of food science and postharvest technology of the Hawassa University. He worked as lecturer in Debub College, Ethiopia. He is working on food product development and safety. Ali Mohammed is a professor of food and postharvest technology. He has been lecturing in the department of food science and postharvest management and head of the department in Jimma University, Ethiopia.