The main purpose of this study is to analyse the factorial structure, psychometric properties and predictive capacity for academic achievement of a scale designed to evaluate the time management skills of Spanish high school students. An adaptation of the Time Management Questionnaire was presented to two samples of 350 Spanish high school students. Exploratory and Confirmatory Factor Analysis results from the two samples shows an adequate fit of a three-factor oblique model, as well as its superior explanatory capacity compared to other competitive models considered. This model basically reproduces the structure of the original scale, integrating the subscales on short-range planning, long-range planning, and time attitudes. The psychometric properties of the three subscales also reach satisfactory values. Finally, the predictive capacity of time management skills on academic achievement is examined, especially regarding the scale on Long-range planning. The results are discussed with regard to the prior study on the topic and their instructional repercussions.