Forty market samples of locally produced (33) and imported (7) cereal-based flours used for complementary feeding in some African countries and Vietnam were studied in order to characterise their macronutrient content and, when prepared as gruels, their viscosity, energy density, and osmolality. The results show that less than half were fairly balanced with respect to their protein and lipid content. When prepared as gruels following the manufacturers' instructions, out of the 21 locally produced flours with complete instructions, ten had energy densities too low to provide sufficient energy to complement breastmilk for 9-11-month-old infants even at three meals a day (< 77 kcal or 322 kJ/100 g), nine were satisfactory if fed more than twice a day, and two if fed twice a day (> 116 kcal or 485 kJ/100 g). Two of the 11 with acceptable energy density had osmolality values higher than those reported in literature for complementary feeding (< 660 mOsm/kg H2O). In addition, when prepared as gruels with viscosities within the range of viscosity (1 to 3 Pa.s) usually observed in African countries, 14 of the 32 (44%) locally produced flours had insufficient energy densities to meet the energy requirements of infants even at three meals a day. These results call for greater concern and effort towards improving the nutritive value and energy density of cereal-based complementary foods produced in developing countries.