The present study analyzes the psychometric properties of the Career Decision Self-Efficacy Scale-Short Form (CDSE-SF) in a sample of Portuguese secondary education students using the Rasch model. The results indicate that the 25 items of the CDSE-SF are well fitted to a latent unidimensional structure, as required by Rasch modeling. The response scale, containing 5 categories, showed proper functioning; therefore, the people and item parameters could be estimated with high precision (0.89 and 0.97, respectively). Differential item functioning (DIF) analyses confirmed that there were no differences in the results of the CDSE-SF concerning gender. Finally, psychometric implications derived from the results of the present study are discussed, and suggestions are provided for future investigations. (Contains 1 figure and 2 tables.)