The aim of this study is to examine the psychological and environmental vari­ables which are related to the mathematics achievement of third-year students in Jamaican post-primary schools. A correlational study of the inter-relations of thirteen independent variables with the criterion, mathematics achievement, was factor-analysed to produce four factors which account for most of the variation in mathematical performance. These four factors are related to (i) the social en­vironment of the student; (ii) affective personality traits characterised by the student's perception of his ability to do mathematics; (iii) the teachers of mathe­matics; and (iv) the degree of the urbanisation of the school's community.