Business analysis is an essential component of the continuous growth and strategic plan of every company. By carefully considering how the business is conducted, what is going well and what could be better, the management of the organization sets itself on the path to future success and sustainable development. Business performance is usually carried out by the top-down method, ie it begins with a macroeconomic analysis of the environment, then the immediate environment of the company, and then an analysis of the business performance of the company itself. The subject of this thesis is the business analysis of Gradska Plinara Zagreb d.o.o. (in further text: GPZ) The main goal of this paper is to determine the financial position and business success of the company GPZ. The analysis will begin with the application of the company's external environment analysis model, such as the PESTLE model and Porter's 5 force model, followed by a diagnosis and analysis of the company's financial situation, using selected analysis models over the company's primary financial statements. The research will cover a period of 5 years: 2014- 2019. The basis for the theoretical chapters will be available scientific and professional literature, while the empirical part will primarily use secondary data obtained from publicly published financial statements and internal documents of the selected company. The results of the analysis will be shaped through the development of a SWOT model, which will show the fundamental strengths and weaknesses, as well as opportunities and threats of the observed company. The paper concludes with a conclusion in which the basic results of the research will be presented. The expected professional contribution is reflected in the application of selected business analysis methods to a specific company, which will provide a comprehensive analysis of its external environment and business evaluation and assessment of sustainable development of the gas distribution in Zagreb and Zagreb County.