Analyzed the dimensionality of the German version of Rosenberg's Self-Esteem Scale (RSES) in a nationally representative population sample of 4,988 subjects (46.4% males; aged 14-92 years). Using confirmatory factor analysis, 1- and 2-dimensional models were tested. Results suggest that the RSES is a 2-dimensional scale comprising the highly correlated components positive and negative self-evaluation, which constitute a unitary construct of global self-esteem at the second-order level. In order to obtain a more conclusive solution, an item response theory (IRT) analysis (partial credit model) was conducted. Results lend support to a 1-dimensional view of the RSES. Furthermore, psychometric properties and norm values based on the representative sample are reported. Analyses revealed extremely high response probabilities for all items, as a consequence of which self-esteem cannot be differentiated at the upper end of the range.