The Memory Characteristics Questionnaire (MCQ) was developed by Johnson, Foley, Suengas, and Raye (1988) to assess the characteristics of memories of external and internal origin, postulated in the source monitoring model (Johnson, Hashtroudi, & Lindsay, 1993). The MCQ was translated into Spanish using a back-translation method. Psychometric properties of the translated MCQ were tested using responses collected from an experimental study simulating a forensic context. Ten police officers and 8 psychologists individually interviewed 240 university students who completed the MCQ after reporting what they had seen in a film. Half of the participants were asked to tell the truth, while the other half were asked to lie. The results have shown adequate psychometric properties of the Spanish MCQ items for the total sample and across experimental conditions. Cronbach’s alpha value was .79 for the total sample, .78 for the honest condition, and .76 for the lie condition. Validity evidence of dimensionality supports that the factor structure of Spanish MCQ was equivalent to that proposed by the authors of the original version. Also, a two-factor ANOVA (video clip x condition) was performed to analyze experimental data. Neither interaction effects, F(236) = 1.189; p = .277, nor main effects were found to be significant between those asked to tell the truth and those asked to lie. These results demonstrate that the Spanish MCQ has adequate psychometric properties.