Barnyard millet is one of the major crops and nutritionally superior to other cereals. It is an excellent source of nutrients and also contains moderate amounts of anti-nutrients such as tannin, phytic acid, and phenolic compounds. Traditional processing techniques enhance the edibility, nutritional quality, and reduce anti-nutritional factors. In the present study, an attempt was made to formulate barnyard millet flour-based diarrheal replacement fluid and analyze the effect of roasting and soaking methods on nutritional composition, viscosity, osmolarity, and sensory characteristics. The results showed there was a significant difference in nutritional, anti-nutritional, viscosity, and osmolarity properties of differently processed barnyard millet flour. Soaking of millet reduced the anti-nutritional factors such as tannin (2.21±0.01-2.96±0.03 mg/100gm) and phenolic compound (5.2±0.01-5.31±0.01mg/100g), similarly, roasting significantly increased the nutrients, and also lowered the viscosity of the replacement fluids (267.31±0.02 -543.90±0.09cP). The osmolarity of enzyme-treated roasted millet replacement fluids was comparable to the normal osmolarity range of plasma (275-295mOsm/kg). Roasted barnyard millet-based diarrheal replacement fluids had better sensory properties than raw and soaked millet. The mineral composition, viscosity, and osmolarity of roasted barnyard millet suggested that it has preferable attributes as a diarrheal replacement fluid.