KMEČOVÁ, Juliana: Mystery shopping as a tool of evaluation of provided services in a selected company: [Diploma thesis] - Technical University in Zvolen, Department of Marketing, Trade and World Forestry. Thesis supervisor: Ing. Miriam Olšiaková, Ph.D. Zvolen: TU, 2020, 71 p.The aim of the diploma thesis is to evaluate the level of services provided in selected Planeo stores through the mystery shopping method. The work consists of two basic parts, theoretical and practical. In the theoretical part, we focused on the theoretical basis of mystery shopping and trends in the world in this area. In the practical part we perform mystery shopping in ten Planeo stores in the Slovak Republic, in the Banská Bystrica and Žilina regions. We evaluate stores according to a pre-compiled questionnaire and we evaluate stores individually as well as in mutual comparison. Based on the evaluation of the level of services provided, we set proposals and recommendations for the correction of identified deficiencies.