The Strengths and Difficulties Questionnaire (SDQ) is a well-known, widely used and well-established brief screening instrument for detecting psychological morbidity in childhood. However, no research has been conducted with Spanish samples to provide data about the validity and reliability of this instrument, or the factorial structure of the questionnaire. The current instrumental study aims to provide the psychometric properties of the Spanish version of the SDQ. A sample of 595 children was evaluated using both teachers and parents as informants. Descriptive statistics for the SDQ are presented. Cronbach’s alpha coefficient, was calculated for the full global questionnaire and each of its scales, to examine the internal reliability. Factor analysis with Varimax Rotation was conducted following the original author’s recommendations. The factor solution was analyzed using Confirmatory Factor Analysis. Data showed a satisfactory index of reliability as well as a factorial structure of five dimensions with some exceptions for some items. We conclude that our study replicates the data found in other studies in which the goodness of the SDQ as a screening instrument has been studied.