This paper reports the preliminary results of an investigation aimed at analyzing the interaction between teachers' self-efficacy beliefs about differentiated teaching strategies (instruction, behavior management, and collaboration) and the satisfaction of the basic needs for relatedness, autonomy, and competence. The participants were 861 Portuguese teachers from 1st to 9th grade (elementary to high school). For data collection purposes, three scales measuring Teacher Effectiveness for Inclusive Practices, the Teacher Professional Achievement Scale, and a questionnaire assessing Pedagogical Differentiation Strategies were used. Data were analyzed using exploratory and confirmatory factor analysis, structural equation modeling, correlations, and multiple regression analysis. Preliminary results show that experience predicts in a negative way teacher self-efficacy for using inclusive practices and in controlling behavioral effectiveness, as well as female teachers perceiving themselves as more competent in using inclusive teaching strategies. In addition, the results showed that female teachers perceive greater needs for relationship satisfaction and competence than male teachers. Finally, male teachers perceive themselves as having more difficulty in building inclusive environments.