Nowadays, the new enterprises are recognized as the main source of job creation, innovation and development. In today's business world, new enterprises are recognized as an important source of job creation, innovation and development. Therefore, identifying influencing factors that play key roles in the start-up of Small and Medium Sized Enterprises (SMEs) is critical. Thus, the purpose of this study was to identify critical factors for starting-up Small and Medium sized Sport Enterprises (SMSEs) companies whose business is sport and developing a conceptual model that might be used by entrepreneurs in sport business. The methodology was qualitative. Interviews were conducted with 18 individuals, selected through purposive sampling, involved in sport-related SMEs. After a careful investigation of enterprise start-up models in the literature, and based on the results of experts interviews, an integrated approach was indicated as popular models were used by SMEs scholars. Then, a model was proposed in line with integration approach.The conceptual model is based on the integrative approach and shows that three important categories of factors were indicated: Individual; 2.individual factors; Environmental; and 3.environmental factors; and Financial factors.financial factors. It should be mentioned that these factors were constitude of subdimentiones.