Friendship is an important bond in the personal and social growth of an individual and plays a prominent role during youth. Most scales to measure it are aimed at children and adolescents but none measure character friendship, a type of selfless friendship with ethical traits an d Aristotelian roots. Therefore, the aim of the research is to design and validate the youth Character Friendship Scale (CFS) in a sample of 1587 young Spanish people. The final version of the CFS is composed of 35 items distributed over three dimensions: "Selfless love and intimacy" (21), "Trust" (7) and "Respect and forgiveness" (7) with ordinal reliability coefficients of 0.94, 0.79 and 0.7 respectively and good model fits (CFI = 0.986; TLI = 0.986; RMSEA = 0.043; SRMR = 0.054; GFI = 0.997). It is concluded that the CFS is a scale with good psychometric properties for measuring character friendship in young adults. The results obtained from its application will lead to a better understanding of the importance of character friendship for the socioemotional development or happiness of young adults and will enable the development of intervention programmes that enhance aspects of friendship such as trust, respect, forgiveness or mutual knowledge, which can facilitate collaborative relationships and contribute to social cohesion
