Malnutrition in Nigeria can be attributed to poor nutritional quality of cereals like maize and millet that are mostly fermented and processed to gruel for infant’s consumption. Nigerians under-utilize Pigeon pea, carrots and sweet-potato as in infant complementary food despite their abundance. This study evaluated the nutritional quality of co-fermented maize/carrot/pigeon pea (MACP) and millet/sweet potato/pigeon pea (MISP) in ratio 50:20:20 as infant complementary foods. Proximate chemical composition, anti-nutritional factors, protein solubility and functional properties of MACP and MISP in terms of infant complementary food after 72hours fermentation time were analyzed using standard analytical methods. Statistical analyses all experiments were conducted in triplicate. A one-way analysis of variance was performed with P 0.05) energy value than the recommended 4kcal/g (on dry matter basis). Carbohydrate and dietary fiber values met the required values based on average breast milk intake. In anti-nutritional factors: TA( 2.05-1.10), Phenol( 1.02-0.48), Saponin ( 2.25- 2.36), Alkaloid (1.15-1.12), Flavanoid ( 0.35-0.28) Phytin(4.35-5.03) , Oxalate (0.68-0.81) and Cyanide(1.27-1.28). The antinutritional factors significantly (p0<05) reduced in sample MISP than in MACP. MACP sample had higher PS% in the pH range of 1-4, and significantly higher (p0<05) in the pH range of 10-12. While MISP had higher PS% in the pH range of 6-9. Both samples in terms of functional properties could be useful in structural interactions in foods, flavor retention, improved palatability and shelf life extension. In terms of general acceptability sample MACP was preferred while MISP was preferred in terms of color. The sample MACP was more enhanced in amino acids except in tryptophan compared to MISP .KEY WORDS: co-fermentation, cereals, legumes, tuber, nutrients.