Asymmetric stress-controlled fatigue i.e., ratcheting behaviour of a non-conventional stainless steel X12CrMnNiN17-7-5 has been investigated with varying mean stresses, stress amplitudes and number of cycles at room temperature using a servo hydraulic universal testing machine. The X-ray diffraction profile analysis using the modified Williamson–Hall equation has been carried out in order to estimate the dislocation densities in the specimens subjected to ratcheting deformation. Increase in strain accumulation has been explained by the increase in dislocation densities in the ratcheted specimens and a correlation between the strain produced by ratcheting deformation and the estimated dislocation density has been established.