This study investigated the role of metacognition as a mediator of the effect of test anxiety on a surface approach to studying. The following scales were completed by 109 undergraduate social sciences students: Approaches and Study Skills Inventories for Students (ASSIST), Metacognitions Questionnaire (MCQ), and Test Anxiety Scale (TAS). Positive and significant correlations were observed between test anxiety and a surface approach to studying, and between all five dimensions of metacognition and test anxiety. Positive and significant correlations were also found between four of the five dimensions of metacognition and a surface approach to studying. Structural equation modelling was used to test a mediational model in which test anxiety predicted metacognition which in turn predicted a surface approach to studying. The results supported the hypothesis that the effect of test anxiety on a surface approach to studying is entirely mediated by metacognition. The practical implications of these findings are outlined. (Contains 1 table and 1 figure.)