In this graduate thesis an interlaboratory comparison is carried out on hardness testing according to HV10 in theoretical and experimental terms. A certified reference standard block for HV10 is used. The theoretical part of this paper outlines the main features of hardness as a physical size and highlights the basics of hardness measurement. The Vickers method of hardness testing is described in more details. Futhermore, any measurement problems regarding the Vickers method of hardness testing are explained. In the experimental part of the thesis the planning and implementation of interlaboratory comparison is explained. All measurements are carried out in laboratories that are participants of the intelaboratory comparison. The obtained measurements are analyzed and based on them an appropriate conclusion is made regarding the fact if the participants are capable of carrying out the hardness measurements toward Vickers.In this graduate thesis an interlaboratory comparison is carried out on hardness testing according to HV10 in theoretical and experimental terms. A certified reference standard block for HV10 is used. The theoretical part of this paper outlines the main features of hardness as a physical size and highlights the basics of hardness measurement. The Vickers method of hardness testing is described in more details. Futhermore, any measurement problems regarding the Vickers method of hardness testing are explained. In the experimental part of the thesis the planning and implementation of interlaboratory comparison is explained. All measurements are carried out in laboratories that are participants of the intelaboratory comparison. The obtained measurements are analyzed and based on them an appropriate conclusion is made regarding the fact if the participants are capable of carrying out the hardness measurements toward Vickers.