The present study sought to understand the nature and level of foreign language (FL) anxiety among primary school students and the relationship between FL anxiety and FL achievement. Changes in FL anxiety across groups of three primary school years were also examined. A total of 631 (324 male, 307 female) primary school students aged 9-11 years completed the Foreign Language Classroom Anxiety Scale (FLCAS) that measured students' FL anxiety. Our participants' FL achievements as measured by low-stakes regular assessments and high-stakes formal examinations were also collected. On average, primary school students reported levels of FL anxiety comparable to those of adults observed in previous studies. Factor analysis on FLCAS generated four components of FL anxiety: communication apprehension, fear of negative evaluation, test anxiety and negative attitude towards classroom. Correlation analyses showed that students' FL anxiety was inversely correlated with their FL achievements. The correlation was stronger for formal examinations with higher stakes as compared to regular assessments with lower stakes. Finally, the correlation strengthened as a function of higher instructional level. Results are discussed in relation to previous research. Implications to FL education are also considered.