Tromont d.o.o. is one of the largest construction companies in Dalmatia. According to the company's activities, it can be said that it has a lot of competition in its areas, but regardless of that, Tromont d.o.o. successfully rivals the competition and contracts the biggest deals. A large part of the business is focused on major construction renovations, so Tromont d.o.o. can boast in 2020 the completed reconstruction of the student dormitory Bruno Bušić in Split, and the reconstruction of KBC Dubrava in Zagreb. The aim of this paper was to analyze the costs of Tromont d.o.o. in the period from 2016 to 2020. Using vertical and horizontal analyzes, the values of the decrease and growth of the share of costs were obtained both for which analysis and in which period. Further on the topic of vertical analysis, the obtained values represent the percentages of costs in total costs, and it was concluded that a large share of costs in the companies Tromont d.o.o. in the observed period it belongs to operating expenses. When it comes to horizontal cost analysis, then the obtained values have a significantly larger decline or increase due to the fact that the base is taken the previous year than the current observed. Also used calculations of the share of fixed and variable costs in the total cost led to the conclusion that the observed company, in this case Tromont d.o.o. in the observed period from 2016 to 2020 has very justified costs, without any significant or unrealistic deviations, and in accordance with the activities of the observed company.