Little is known about the factorial invariance and latent mean difference across sex and age in trait emotional intelligence (EI). The purpose of this study was to examine whether the measurement structure underlying trait EI is equivalent across sex and age groups. The sample consisted of 2919 teenagers, youths and adults. In order to investigate the above hypothesis the measurement and structural equivalence as well as the equality of latent means of scores across sex and age were tested. The multi-group confirmatory factor analysis results revealed that configural, metric, scalar and structural invariance exist across sex and age samples. Findings regarding the latent mean differences across sex and age groups are discussed with reference to recent and past findings.