The grape is a highly nutritious fruit that is widely consumed throughout the world. The wine and juice industries produce a residual biomass mainly composed of bark, seeds and stalks (grape stems). Residual grape waste is rich in phenolic compounds, and the use of these compounds has an important impact on the reduction of agroindustrial waste as well as the possibility of creating products with high aggregated value. The objective of this study was to determine the physicochemical characteristics of mixed grape seeds (juice production waste) of the Cora and Izabel varieties. The physicochemical characterization of the seeds was performed by determining the mean seed diameter (Digimess digital micrometer with 0.001 mm resolution), weight (analytical balance), moisture (heated chamber at 105 °C), ashes (muffle furnace at 550 °C) and lipids (Kjedahl method, correction factor 6.25). The mean diameter and weight of the whole seed was 2.87 μm and 0.043 g, and for the parameters moisture, ashes, proteins, and lipids were 13.18 ± 0.17%, 1.47 ± 0.04%, 4.95 ± 0.91%, and 11.10 ± 0.40%, respectively. The obtained value for protein is below the value found for grape seeds of the Cabernet Sauvignon variety. The results for lipids, ashes, and moisture are comparable to values found for other varieties of grape seeds. Drawing from the results obtained in this characterization,it is possible to verify that this residue shows great potential for use in the extraction of oils or other direct applications, such as use in animal feed, in addition to contributing to a reduction in the environmental impact provoked by inappropriate disposal of grape seed waste.