The coconut and oil palm are members of the Arecaceae. Despite a recent revised classification of this family, uncertainties still remain. We evaluated the taxonomic potential of the carbohydrate reserves by comparing these two palm species, belonging to different subtribes within the same Cocoseae tribe. We showed that both palms share features with all palm taxa but differ by others. We showed that the coconut and oil palm exhibit common but also distinct characteristics leading to different carbohydrate patterns as potential markers. Indeed, both palms, like all palms, store their reserves mainly in the stem but, in contrast to numerous palms, do not use starch as major reserve pool. Both palms share the use of soluble sugars as reserves but differ in the nature of the dominant sugar (sucrose or glucose), the amount of starch and in the total amount and distribution of the reserve pool. Each palm, thus, exhibits a particular carbohydrate profile, based on similarities and differences, reflecting their relationships within the family and within the Cocoseae tribe such as their distinct biological features. These profiles might be an aid for taxonomic and evolutionary studies of Cocoseae palms, combined with anatomical, morphological and DNA markers.