The success of the new product development (NPD) process is vital for the survival of projects. Especially for small entrepreneurial projects that try to survive in a very competitive environment, affected by constant market and technical changes. Previous literature emphasize the importance of the generation of new ideas, to improve the product concept during the pre-development stage, but it did not pay a lot of attention to the sources of ideas. For this reason, this study aims to develop the knowledge concerning the sources of ideas of small entrepreneurial projects, during the fuzzy front-end (FFE). The literature review of this study presents the previous researches that relate to the sources of ideas, during the idea generation stage of the FFE. The structure of the existing model, integrating the sources of ideas, is based on three categories: environmental scanning, innovative organizational culture and joint research. An inductive study and a research, based on the analysis of one small high-tech entrepreneurial project, were conducted to cover the literature gap. This choice of methodology reflects the experimental purpose of this research. The empirical data are only primary data, collected by analyzing the diaries of the two entrepreneurs involved in the project. Our findings reveal that contact with lead user, entrepreneur experience, customer involvement, brainstorming sessions, competitor analysis, resource constraints and prototype conception represent the main sources of ideas of small entrepreneurial projects in the FFE. The practical purpose of this study is to offer some advices to entrepreneurs of small entrepreneurial projects for accessing to sources of ideas, during the idea generation stage of the FFE, and manage their impact on the development of the product concept. The theoretical implications contribute to the identification of new sources of ideas and a proposition of framework of their impact.