In this paper, we study the early stages of atherosclerosis with a mathematical model based on reaction–diffusion equations in order to describe the emergence of fatty streaks, considered as precursors of atherosclerotic plaques. The model introduces a novel approach by studying the interaction between inflammation and chemotaxis in the same framework. It includes the main factors in atherosclerosis to describe inflammation and considers simultaneously the chemotactic movement of macrophages to address the positive feedback between the inflammation and chemotaxis and its impact on the disease evolution. Stability analysis and numerical simulations for a reduced model including macrophages and inflammatory cytokines show the formation of spatial structures corresponding to the emergence of fatty streaks as a result of interaction between chemotaxis and inflammation. Numerical simulations are performed in 1D and in 2D. Likewise, we consider the complete model taking into account also endothelial cells and growth factor provides a more realistic description of the disease and extend the results obtained by performing numerical simulations. © 2025 Elsevier B.V., All rights reserved.