This study aims to examine the psychometric properties of the Self-Esteem Scale (SES; Rosenberg, 1965) through the Classical Test Theory (AFE) and the Item Response Theory (Mixed Rasch Model). The SES has been administered to 2000 subjects (1012 male, 988 female) with a mean age of 39.18 years (SD = 15.87). Exploratory Factor Analysis pointed out a two-factor solution with a submeasured factor (item 3, 4, 7 in this version). The Mixed Rash Model analysis showed tree different Latent Classes, two of which (Class 1, Class 3) with related trend. These results can support further on the hypothesis of bi-dimensionality of the self-esteem construct and unimportant the reduced number of items in the second factor.