There are no published data on the factor structure of the Multidimensional Anxiety Scale for Children (MASC) among adolescents in the Cape Town metropole of South Africa. The objectives of this study were (i) to establish the exploratory factor structure of the MASC using a principal components exploratory factor analysis (EFA); (ii) to confirm the derived factor structure using confirmatory factor analysis (CFA); and (iii) to examine gender, age, and race effects among adolescents in the Western Cape of South Africa. A convenience sample of 1,051 adolescents was selected from nine different schools in the Cape Town metropole of South Africa. An EFA yielded a four-factor structure congruent to the factor structure established previously in other samples. Furthermore, the CFA showed that the four-factor structure fit the data well. Black participants reported significantly higher levels of Harm Avoidance than other racial groups, and Black and Coloured (mixed race) participants reported significantly higher levels of Anxious Coping than White and Asian participants. Black and Coloured participants reported significantly higher levels of Separation/Panic than White participants, and Black participants reported higher levels than Asian and Coloured participants. Finally, there were no significant age effects, but females scored significantly higher overall and on all MASC subscales. The MASC seems to be a useful tool for assessing and distinguishing anxiety symptoms among adolescents in the Cape Town metropole of South Africa.