Introduction: This study examines the relationship between student basic need satisfaction (autonomy, competence, relatedness and belonging), their reporting of approaches to learning (deep and surface), their reporting of avoidance strategies (avoidance of effort and challenge, avoidance of help seeking and preference to avoid novelty) and achievement in subject-matter domains. Method: The sample was composed of 157 Spanish undergraduate students. Self-report questionnaires were used to measure the construct selected for this study and their interrelationships were examined using structural equation procedures. Results: In general terms, we have proved that basic needs satisfaction, when satisfied, encourage the use of the deep approach to learning and, in turn, the decrease of students' avoidance strategies. In contrast, when these needs are not satisfied, the use of the surface approach to learning is encouraged, consequently, leads to an increase in students' avoidance strategies and achievement. Conclusions: The results suggest that approaches to learning and avoidance strategies may play a mediator role between student psychological needs and student achievement. Implications for pedagogical practice are discussed. (Contains 4 figures and 2 tables.)