The grow in polymer production is influenced by the high demand from the packaging sector. Expanded polystyrene (EPS) is one of these materials that is widely used in disposable packaging, however, generating waste that occupies a large volume, besides being of difficult degradation. Starch, a naturally occurring and biodegradable polysaccharide, would be an alternative in the search for a renewable source material. However, starch foams have some limitations related to their hygroscopicity. The objective of this study wasto analyze the influence of silica content (1, 2 and 3%) on the cell structure and surface hygroscopicity of cassava starch foams. The foams containing starch, glycerol and water wereproduced by thermo‐compression molding. Results showed that, at lower contents, silica acted predominantly as a nucleating agent, generating smaller cells in the foam. At the higher silica content, it played a more efficient role in reducing the affinity of the starch for water. The formulation with 2% silica showed the highest density (0.232 g/cm3), impact strength (2067 J/m2) and contact angle (84.8°).This article is protected by copyright. All rights reserved