Transparency is a problem addressed by many authors in a variety of areas but there are no tools that allow it to be measured. This hinders our ability to better understand the phenomenon, and in the long run, influence it. Due to this lack of standardized tools for examining the perception of transparency level, an original Transparency Perception Questionnaire was developed and used in this research for the first time. The preliminary study was conducted using the example of project teams. The questionnaire is characterized by high accuracy and reliability, and the evaluation was based on principal component analysis (factor analysis) and Cronbach’s alpha coefficient. In the factor analysis, three scales of the tool were distinguished which evaluated the perception of the transparency level in the teams: directional, methodical and explanations transparency. In the last stage of the preliminary study, an analysis of descriptive statistics was used to answer the research questions. The results of the analysis made it possible to recognize the statistically significant differences in the perception of transparency level. Differences in perception occurred both between the types of transparency assessed by the managers and team members, as well as in the perception of the same type of transparency between the managers and team members (explanations transparency).