Term entrepreneur is often identified with success, wealth and prestige. Media paint a false picture of instant success for everyone who decide to embark on path to entrepreneurship. In reality one has to have certain qualities, skills and knowledge in order to become a successful entrepreneur. It requires creative problem solving, ambition and will to take risks. Entrepreneur must be prepared to take risks in order to generate profit. However, there are certain tools entrepreneur can use to anticipate and reduce that risks. One of those tools is business plan. Business plan is a written document which enables entrepreneur to quantify its idea or in other words put in ratio necessary investments and projected earnings in order to check cost effectiveness of the project. Potential threats are also evaluated to determine project sensitivity and minimise their effects. This paper aims to determine what is a business plan, how to use it and what are the effects of business plan to entrepreneur and development of his entrepreneurial idea. As an example, already existing business plan will be used. It is an elaborate of the entrepreneurial idea, requested by the entrepreneur, to provide financial resources for acquiring speed boat for the purpose of expanding range of services offered by the tourist agency.