The present study was initiated to evaluate the nutrient composition and microbiological quality of composite flours based on fonio, soybean and mango for possible use as complementary food for children aged 6-24 months. For this purpose, four composite flours CF1 = 90: 10: 0, CF2 = 80: 15: 5, CF3 = 70: 20: 10 and CF4 = 60: 30: 10 were formulated from fonio, soybean and mango flour ratio respectively. Chemical analyses showed that these composite flours contain 6.18-15.25% crude fat, 10.73-11.35% crude protein, 48.60-66.55% carbohydrates and 355.37-384.39 kcal of energy, which are close to the standard recommended by World Health Organization. However, the composite flours had levels of calcium (13.46-22.78 mg/100 g), vitamin C (12.40-32.70 mg/100 g) and iron (4.27-7.73 mg/100 g) lower than standard values. The in vitro digestibility of the formulations showed that CF2 was more hydrolyze than the other composite flours with 301 µg of glucose released in 3 hours. With regard to the results of microbiological analyzes, all germs of hygienic interest (mesophilic aerobic germs, total coliforms, yeasts and molds, enterobacteria and Staphylococcus aureus) were found with loads below the recommended microbiological standards. However, CF3 was outside of the recommended limits in terms of Staphylococcus aureus loads. This study revealed that the formulated complementary foods from local products have great potential in providing nutritious foods for children. This is promising for regions where protein-energy malnutrition is prevalent.