Self-determination theory (SDT) has been the subject of pioneering studies in recent years. SDT is centered on the basic psychological needs of autonomy, competence, and relatedness and their necessary role in self-determined motivation, well-being, and growth. The objective of the present research was to investigate the relationships between learning style preference, motivational regulation, and psychological well-being of 417 EFL students at the intermediate level in private schools in three provinces in Iran. The researchers collected the data via electronic surveys using the Perceptual Learning Style Preference Questionnaire, Academic Motivation (AM) Scale, Basic Psychological Needs Satisfaction Measure, and Psychological Well-Being (PWB) Scale. The quantitative analyses using structural equation modelling showed positive correlations between the learning style preferences and AM and the PWB. Moreover, the satisfaction level with needs was a significant factor in predicting AM and PWB scores. The study highlights the importance of recognizing and accommodating diverse learning styles in educational settings and the significance of needs satisfaction in fostering intrinsic motivation and overall well-being among EFL learners. These findings emphasize the need for practitioners to target and tailor their pedagogical strategies to meet the needs of their learners and create a learning environment that fosters the three psychological needs as determined by SDT.