During the start-up phase, organizations face additional challenges related with their lack of self-sustainability and low maturity. In the field of project management, any start-up business risks undesirable performance in delivery if the right actions are not taken at the right time. The purpose of this thesis is to gain an in depth understanding of the importance of introducing an integrated project management approach in start-ups and to provide the reader with selected knowledge, tools and techniques for the implementation of an adequate framework which is scalable according to the growing size and needs of the business. In order to acquire the data and knowledge needed for this undertaking, an in-company project is executed in Truphone Ltd which serves as a practical example of a start-up business in the area of telecommunications. Research results from the field are collected through direct observation and participation by the author and by the use of other methodologies like personal interviews and electronic surveys with employees. The aggregation of these practical evidences with the outcome of a literature review on general project management theory and on the culture and needs of start-up businesses, leads to a proposal for a solution approach involving three main dimensions: project management, organizational structure and personal skills