This paper presents a structural continuum framework for hyperelastic modelling of arterial layers with distributed collagen fibre orientations. The goal is to develop a new hyperelastic free-energy function that accurately represents the anisotropic elastic properties of adventitial and intimal layers of arterial walls. The model incorporates an additional scalar structure parameter that characterizes the dispersed collagen orientation. The framework accounts for the dispersion of collagen fibre orientations, which is crucial for accurately capturing the stress–strain response of these layers. The model is implemented in a finite element framework and validated using experimental data from human iliac arteries. The model is shown to effectively capture the mechanical response of the adventitia, particularly under inflation and uniaxial tension. The paper also reviews existing constitutive models for arterial walls, highlighting their limitations in representing the dispersion of collagen fibre orientations. The proposed model generalizes previous fibre-reinforced structural models and incorporates a scalar structure parameter to account for the dispersed collagen orientation. The model is validated using experimental data and shown to provide accurate predictions of the mechanical response of arterial layers. The paper emphasizes the importance of considering the structural organization of arterial layers in the development of constitutive models for soft biological tissues.This paper presents a structural continuum framework for hyperelastic modelling of arterial layers with distributed collagen fibre orientations. The goal is to develop a new hyperelastic free-energy function that accurately represents the anisotropic elastic properties of adventitial and intimal layers of arterial walls. The model incorporates an additional scalar structure parameter that characterizes the dispersed collagen orientation. The framework accounts for the dispersion of collagen fibre orientations, which is crucial for accurately capturing the stress–strain response of these layers. The model is implemented in a finite element framework and validated using experimental data from human iliac arteries. The model is shown to effectively capture the mechanical response of the adventitia, particularly under inflation and uniaxial tension. The paper also reviews existing constitutive models for arterial walls, highlighting their limitations in representing the dispersion of collagen fibre orientations. The proposed model generalizes previous fibre-reinforced structural models and incorporates a scalar structure parameter to account for the dispersed collagen orientation. The model is validated using experimental data and shown to provide accurate predictions of the mechanical response of arterial layers. The paper emphasizes the importance of considering the structural organization of arterial layers in the development of constitutive models for soft biological tissues.