The paper presents the results of rheological measurements of five selected ketchups available on the Polish market. Rheological identification was carried out in rotary shear conditions and using forced oscillation. The equilibrium flow curves (shear at constant and stepwise increasing values of shear rate) were determined, and the thixotropic effect in the form of shear hysteresis loop under conditions of shear at increasing and then decreasing shear rates. The values of the dynamic storage modulus, the loss modulus and the complex viscosity modulus were determined in dynamic measurements. The water content was also measured, and qualitative characterisation of the structure was made on the basis of photographs taken under conditions of shear interferometry. The research revealed significant differences in rheological properties and structure of the ketchups examined. All the media showed a significant thixotropic effect. The values of apparent viscosity of the ketchups did not depend on water content but primarily on the consistency stabiliser used. The presence of modified starch had a significant impact on the flow curves, and thus on the rheological properties. The presence of tomato cell walls in ketchup structure caused the appearance of discontinuity in the flow curves at low shear rates and lower storage modulus values. It was also demonstrated that the ketchups studied did not meet the Cox-Merz equation.