The in vitro starch digestibility (IVSD) method (“as-is” or modification) was used to assess the digestibility of two sweetpotato-based complementary food (CF), denoted orange-fleshed ComFa and cream-fleshed ComFa, and two cereal-based CF: Cerelac (wheat-based commercial infant cereal) and Weanimix (maize-soybean-groundnut blend). Using the IVSD method (“asis”), the sweetpotato formulations with high maltose (averaging 22.24 g/100 g) and low starch, about 15.15 g/100 g, had far lower digestibility values of 6.29 g/100 g, a quarter of that for Weanimix, which contained maltose and starch at levels of 2.72 g/100 g and 48.38 g/100 g, respectively. Further, the IVSD method employed “as-is” estimated the digestibility of Cerelac to be 11.53 g/100 g, about half the value for Weanimix. Conversely, for the modified method, the sweetpotato-based formulations had estimated digestibility value about 3 times higher than Weanimix (63.91 g/100 g), and 1.5 times higher than Cerelac (117.76 g/100 g). The IVSD method (“as-is”) gives false negative results when used to estimate the digestibility of CF that contain significant amount of endogenous maltose. Therefore, its application to predict the suitability of CF warrants further validation.