Purpose - This paper aims to present stability of a three-layered journal bearing considering magnitude of the layers' thicknesses and viscosities with slip/partial slip on the bearing surface. Design/methodology/approach - Modified Reynolds equation based on one-dimensional analysis is derived for a three-layered journal bearing with slip/partial slip. Dynamic coefficients are derived based on infinitesimal perturbation method. Linearized stability analysis is presented taking into account slip/partial slip on bearing surface; thicknesses and viscosities of bearing surface layer; and core layer and journal surface layer. Findings - Results of threshold speed and critical whirl frequency ratio coefficients (C�, CΩ), stiffness (Kij for i = x, y) and damping (Bij for i = x, y) coefficients and threshold speed (�s) and critical whirl frequency ratio (Ωs) are presented. The bearing surface is analyzed for slip (total surface with slip) and partial slip (partial surface with slip). The slip-on bearing surface reduces stability, while partial slip improves bearing stability. The threshold speed coefficient (C�) decreases with slip on bearing surface. The threshold speed (�s) and critical whirl frequency ratio (Ωs) are influenced by the variation of threshold speed coefficient (C�) and critical whirl frequency ratio coefficient (CΩ), respectively. A three-layered journal bearing with partial slip and thick high viscosity bearing surface layer results in higher threshold speed coefficient and has a potential to improve stability of journal bearing. The analyses indicate that optimal angular extent of partial slip region (θs) enhances the stability of journal bearing. Originality/value - The paper presents parametric study of stability coefficients (C� and CΩ) and evaluation of threshold speed (�s) and critical whirl frequency ratio (Ωs) of a three-layered journal bearing with slip/partial slip. © 2017 Emerald Publishing Limited.