Extrusion cooking was used to formulate rice and pigeon pea blend with the aim of providing high energy, protein enriched and affordable foods for malnourished children. Three (3) factors (screw speed, feed moisture content and feed blend composition) affecting the extrusion cooking process were subjected to Central composite design (CCD) and functional properties were used to optimize production variables. Furthermore, the expansion index of 9.56 Â± 0.15, bulk density of 0.05 Â± 0.01 g/ml and water absorption index of 5.55 Â± 0.07 at screw speed of 200 rpm, feed moisture content of 30 % and feed blend composition of 20% (run 12) were obtained. Regression model and response surface plots were developed and tested via coefficient of determination (R2 and adjusted R2), analysis of variance, lack of fit and residual plots. The developed quadratic model showed significant (p<0.05) effect of the process variables on the functional properties of instant porridges from rice-pigeon pea flour blend. Similarly, the coefficient of determination (R2) was found to be 0.96, 0.93, and 0.88, for expansion index, bulk density and water absorption index of the extrudates. Furthermore, lack of fit for the quadratic models were not significant (p>0.05), which suggested that the model equations were adequate in describing the functional properties of the rice-pigeon pea extrudates. In order to optimize the quadratic models, four formulations were prepared and subjected to nutritional and sensory properties where formulation 3 showed higher protein (22.10 Â± 0.01 g/100g), limiting amino acids, (lysine and methionine) of 3.44 Â± 0.04 g/100g and 1.44 Â± 0.02 g/100g, calcium (3.41 Â± 0.07 mg/100g), iron (12.64 Â± 0.03 mg/100g), zinc (9.33 Â± 0.02 g/100g) contents and general acceptability (6.68 Â± 0.06). In conclusion, convenient complementary food was developed from rice-pigeon pea flour blend through extrusion which improved the nutritional and sensory properties of the products.