The objective of the paper was to determine the effect of sucrose and protein added on physicochemical properties of high protein cakes (meringues) made from different whey protein preparations: whey protein isolate (WPI) and whey protein concentrate (WPC). Using protein preparations, solutions were prepared, their protein concentrations were 15 and 20 % (m/v). The protein solutions were whisked in a 2000 ml beaker, in a water bath at 70 °C using a kitchen mixer; the whisking time was 10 minutes. As soon as the volume of the foam produced reached its maximum, and in order to stiffen the systems, sucrose in the form of powdered sugar was added in the amounts of 5, 10, and 15 %. Next, the samples were whisked for 5 minutes. The foam produced in this way was scooped up and placed in 14 mm high aluminium foil baking pans of 50 mm diameter, and stiffened in an oven at 130 °C for 30 minutes. Prior to thermal treatment, the rheological properties of the foams were analysed using a ThermoHaake RS 300 rheometer (ThermoHaake, Karlsruhe, Germany). The yield stress was measured at a constant shear rate of 0.01 s^-1 using a vane tool and a system of parallel plates. Mechanical properties of the protein meringues produced were determined by the use of a TA-XT2i texture analyser (Stable Micro systems, Surrey, Great Britain). Their hardness and crispness were determined; based on a puncture analysis of the texture performed, determined was a force necessary to obtain a 20 % deformation of the meringues. An X-RiteColor® Premier 8200 was applied to analyse the colour of the protein meringues using a CIE L*a*b* system. Measured were the parameters to determine the colour, i.e. L* luminescence as well as a* and b*, which are the coordinates of a point to characterized the colour. The foam, produced from WPI solutions and not thermally treated, was characterized by the best rheological properties and showed the highest yield stress values. The sucrose added caused the yield stress values of foams produced from WPI and WPC preparations to decrease. The mechanical properties of the protein meringues depended on the concentration level of individual ingredients. The samples made from WPI preparations were characterized by the highest hardness values. In the meringues made from the two preparations under analysis, the increase in the sugar concentration caused the hardness to increase and the crispness to decrease. At the same time, it was found that the higher the hardness, the higher the resistance to mechanical crushing. The highest values of L* parameters were reported for meringues made from WPI. The decrease in the protein concentration caused the L* value to decrease in both the meringues from WPI and from the WPC preparations. A higher concentration of sugar in the meringues studied caused the a* and b* colour parameters to increase; i.e. the samples analyzed were greener (less red) and more yellow (less blue).