To analyze whether gender is a source of variability in the General Self-Efficacy Scale (GSES) using Classical Test Theory (CTT) and Item Response Theory (IRT) in a sample of Ecuadorian adults. This is an instrumental study that assesses factorial validity and Measurement Equivalence (ME) across gender using CTT, while IRT is used to estimate item discrimination [a], difficulty [b], and differential item functioning (DIF). A total of 485 adults participated, with 44.9% male and 55.1% female, aged 18 to 53 years (M = 24.29; SD = 7.61). The unifactorial structure of the GSES was confirmed and measurement invariance was established at the thresholds (scalar) level across gender. Furthermore, there are no significant differences (p <.05) in the latent means of the groups. The item parameters for [a] and [b] were found to be adequate, with no evidence of gender-based DIF in the items. The GSES is a reliable scale for use in studies involving Ecuadorian adults, and gender does not significantly affect its measurement propertie
