Plantain is a basic component in the Puerto Ricans’ diet and one of the most economically important crops on the Island. Maricongo crops, the predominant cultivar, do not satisfy the demand for fresh and processed products. The objective of this study was to evaluate the nutritional composition and in vitro digestibility of Maiden and FHIA 20 plantains in stages 1 and 5 and compare these data to Maricongo. Estimated glycemic indexes (eGI) of cultivars under conventional cooking processes (i.e., boiling, fried, baked, and steamed) were performed as well. Baked Maricongo stood out because of its lowest rapidly available glucose value (22.06%), constituting a healthier and the first cooking alternative. eGI values were classified as medium and high, where frying and baking processes presented medium values, and boiling displayed the greatest eGI for both stages. In terms of nutritional profile, this research concludes that Maiden could constitute an option to substitute or supplement Maricongo.