This work shows the relevance of financial analysis in the third sector. This book analyses the importance of the third sector being aware of the implementation of strategic actions in its management decisions based on financial analysis. It also shows the relevance that the application of management methods, namely the application of the ratio method, has not only in the decisions that the CEO needs to take, but also in the current influence they have with clients and future users.The paper shows a bibliographical review of these issues in relation to the combination of the three main themes: third sector, mercies, and financial analysis.