The objective of the present study was to determine the composition of flatbreads prepared from corn and wheat flours supplemented with edible Ecklonia cava, which is a health-promoting medicinal food used as a dietary supplement. The Corn flours used were Whole Blue, Purcell Whole Blue, Purcell Whole Red, Purcell Whole Yellow, Purcell Whole White and Giant White and King Arthur Whole Wheat. Because the colored corn flours are reported to contain health-promoting anthocyanins and the Ecklonia alga contains multiple biologically active polyphenolic and other health-promoting compounds reported to show anti-asthma, anti-cancer, anti-diabetes, antimicrobial, anti-neurotoxicity, anti-obesity, and cardioprotective effects, the resulting flatbreads have the potential for multiple health benefits in humans after consumption. To facilitate the development of the newly created flatbreads for consumption, we determined, using standard methods, the effect of added E. cava on the proximate composition of protein, fat, carbohydrate, dry matter, ash (mineral), and water content of the flatbreads. The unexpected results, for which we have no explanation, show that the measured protein, mineral, and water content of the E. cava-supplemented flatbreads increased, whereas the fat, carbohydrate, and dry matter contents of the E. cava-supplemented flatbreads decreased compared to un-supplemented ones, suggesting that consumers will be able to select flatbreads with a high-protein and low-fat content.