<p>While the Montreal Cognitive Assessment (MoCA) is a reference instrument for cognitive screening, sociodemographic factors such as age and education can affect its diagnostic accuracy. The aims of this systematic review were to characterize the use of the MoCA in samples from Spain and to analyze its psychometric properties. A systematic search was conducted in the main scientific databases up to February 2025. The evidence was synthesized using a dual strategy: a quantitative synthesis (meta-analysis and meta-regression) for the first aim, and a narrative synthesis of psychometric properties guided by the COSMIN framework for the second. Eighty studies were included: 78 (<i>n</i> = 7,457) in the meta-analysis. The mean MoCA score was 22.85, with substantial heterogeneity (<i>I</i>² = 99.3%). Meta-regression explained 62% of this variability, identifying age (<i>β</i> = −0.19/year) and education (<i>β</i> = 1.28/year) as the most significant predictors. Scores were lower in dementia and mild cognitive impairment compared with healthy participants. The narrative synthesis of psychometric properties showed that the MoCA has adequate psychometric properties in the studies conducted in Spain, with good internal consistency (Cronbach’s <i>α</i>: 0.76–0.90) and criterion-related validity (area under the curve: 0.78–0.96). The robustness of the findings was confirmed by sensitivity analyses. In conclusion, the MoCA is a valid and widely used tool in Spain, but its performance is strongly modulated by age and education, supporting the use of adjusted normative data rather than a single universal cut-off.</p>