Bioresorbable iron‐manganese alloys (Fe‐30%Mn) are considered as one of the next‐generation resorbable materials for orthopedic applications. Previous in vitro study showed that Fe30Mn scaffolds with 10% porosity displayed strong mechanical properties and adequate degradation rate without severe cytotoxicity effect. However, the cellular compatibility of these alloys in terms of cell‐to‐cell and alloy‐to‐cell interactions is not ideal. Collagen is the most abundant protein in human bone, providing structural support beneficial to bone healing. We hypothesized that coating collagen on Fe30Mn can improve osteointegration or activities promoting cell adhesion, migration, and proliferation, as the alloy degrades. After preparing collagen coating on Fe‐30Mn via spin coating, we conducted a corrosion test and a direct cytotoxicity test on four Fe30Mn groups: non‐porous and 10% porosity, with and without collagen coating. Furthermore, we evaluated and compared the morphologies of cells over a period of 7 days. Results showed that there was no significant difference between the collagen‐coated and non‐coated groups in corrosion rates, yet a significant decrease from the porous non‐coated group to the porous collagen‐coated group in cytotoxicity level was found. Cell morphology on the porous non‐coated group displayed round shape, whereas that on the porous collagen‐coated group displayed flattened spreading. The study showed that the collagen coating significantly increased the initial cell viability and adhesion for both the porous and non‐porous groups without impeding their degradation rates. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:523–535, 2020