Using the Multicontext Stressors Scale (MSS), this study investigates which factorial structure should be used to measure teacher stressors, and the extent to which this factorial structure of MSS remains invariant across gender. Subsequently, grounded in self-determination theory, the present study also examines the extent to which stressors may differentially predict teachers' psychological functioning. Participants were 584 ( = 45.04; = 8.97) secondary school teachers. Goodness-of-fit indices and estimated parameters of the models, together with latent correlations between stressors, offered support for the six-factor structure, whereas the opposite was true for the one-factor structure of the MSS. Results also supported gender invariance of the MSS. Predictive findings showed that student misbehavior, lack of shared decision-making, and workload stressors are negatively related to basic psychological needs. Likewise, results noted the important role of basic psychological needs to reach optimal teachers' psychological functioning. The results are discussed, arguing the importance of assessing and analyzing teacher stressors using a multifactorial and invariant scale. From a more practical approach, it seems important for school leaders to be especially vigilant about all stressors. Nonetheless, if they desire to prevent detrimental psychological functioning in teachers, special attention should be placed on stressors related to student misbehavior, lack of shared decision-making, and workload.