South Africa participated in the Third International Mathematics and Science Study (TIMSS)in 1995 and its repeat in 1999. In 1995, none of the data on school or teacher level could be analyzed to provide the context for the students' poor achievements in mathematics and science. With the 1999 data now available at both school and teacher levels in addition to the student level data, this backdrop to the results can be provided. Path analysis, using Partial Least Square analysis, was conducted on the TIMSS repeat study (TIMSS-R) data to explore the effect of language and other factors at school level within South African schools on the students' performance in mathematics. The work is currently in progress, but the initial results already indicate the strong relationship between English language proficiency and South African students' achievement in mathematics. The first results from the school level analysis reveals a relationship between the location of the schools, the number of first language speakers in the class, and the role of teacher unions influencing the curriculum to pupils' achievement in mathematics. These and other results of this research are discussed in the paper. (Contains 3 figures, 10 tables, and 43 references.)