The debate on the relative merits of single-sex and co-educational schooling for girls and boys persists. There are also on-going concerns in Australia about declining enrolments in the STEM (Science, Technology, Engineering, and Mathematics) disciplines at both the tertiary and school levels. In this article, we summarise some core findings from the scholarly literature on single-sex and co-educational learning settings and then present official enrolment data from the Victorian Certificate of Education (VCE) for the period 2001--2017 on mathematics and other STEM subjects to determine whether or not attendance at a single-sex school appears to affect participation in these subjects. No consistent pattern was found for boys' and girls' enrolments across VCE STEM subjects by school type (single-sex or co-educational).