Introduction ¿ Mental health is increasingly recognized as a critical determinant of both individual well-being and organizational productivity. However, existing assessment tools in Latin American workplace contexts often lack an integrated approach that captures both psychological distress and positive functioning. Methods ¿ This study describes the development and initial psychometric evaluation of the Latin American Mental Health Scale (LA-MHS), a 30-item multidimensional instrument assessing Anxiety, Stress, Subjective Well-being, and Sleep Problems in working adults. A non-probabilistic sample of 308 workers from multiple Latin American countries completed the scale online. The internal structure was evaluated through theory-driven and data-driven phases, consistent with recommended practices for scale validation. Results ¿ In the theory-driven phase, confirmatory factor analysis (CFA; WLSMV estimator) supported a four-factor correlated structure with acceptable fit, ¿2 (395) = 1025.76, p < 0.001, CFI = 0.933, TLI = 0.926, RMSEA = 0.072, SRMR = 0.062. Internal consistency was excellent for Anxiety and Stress (¿ = 0.91, ¿ = 0.93 for both), acceptable for Well-being (¿ = 0.74, ¿ = 0.84), and below recommended thresholds for Sleep Problems (¿ = 0.68, ¿ = 0.69). A preliminary brief version (LA-MHS-12) was derived, showing acceptable fit in the same sample, although results should be interpreted cautiously due to potential overfitting. In the data-driven phase, exploratory factor analysis (EFA) in a training subsample identified a three-factor structure (Anxiety, Stress including sleep problems, and Well-being), which was subsequently supported in an independent testing subsample (CFA: CFI = 0.927, TLI = 0.920, RMSEA = 0.083, SRMR = 0.078). Reliability estimates were excellent for Anxiety (¿ = 0.91, ¿ = 0.93) and Stress including sleep problems (¿ = 0.91, ¿ = 0.93) and good for Well-being (¿ = 0.80, ¿ = 0.81). Competing models (higher-order and bifactor) were also examined but did not provide clear advantages in terms of interpretability. Discussion ¿ Overall, the LA-MHS demonstrates promising initial psychometric properties, particularly for anxiety and stress. However, further refinement of the well-being and sleep dimensions and additional validation in independent samples are required.
