Stunting is one of the nutritional problems with high frequency in Indonesia. One cause of stunted children is the improper complementary feeding practice. A good quality diet contains macronutrients (protein) and micronutrients (iron, zinc, and calcium) are linearly correlated with children’s growth. A freshwater clam was a local food enriched with highprotein and zinc that is potential to be nutritional complementary foods. However, this was substituted by full cream milk in instant baby porridge. The purpose of this study was to analyze the effect of freshwater clams flour substitution on energy, protein, fat, carbohydrate, fiber, zinc, calcium, and iron as well as physical properties (bulk density, water absorption, and solubility) in instant baby porridge. The design of this study was a single factor completely randomized design with the ratio of freshwater clams flour as substituted in the instant baby porridge as 0% (F0), 5% (F1) and 10% (F2). There was also an effect of substitution of freshwater clamss flour (Pilsbryoconcha exilis) on energy, carbohydrate, protein, fat, moisture content, ash, crude fiber, calcium, iron, and zinc (p = 0.0001) in instant baby porridge. Variation in the percentage of freshwater clamss flour substitution did not significantly influence the bulk density (p = 0.085), solubility (p = 0,05) and water absorption (p = 0.341). Instant baby porridge F0 contained protein, calcium, iron, and zinc less than the requirements. Instant baby porridge F1 had protein and zinc less than the requirements, but calcium and iron levels met the requirements. Meanwhile, the level of protein, iron, calcium and zinc on instant baby porridge F2 met the requirements. Instant baby porridge with the substitution of freshwater clams flour increased the nutrient content which includes protein, fiber, calcium, iron, and zinc but decreased carbohydrate and fat content. Both formulations had a bulk density and solubility which meet the requirement. However, water absorption did not meet the requirements.