This study examines the effectiveness of school-based mental health support for students with Autism Spectrum Syndromes (ASS) in South African cities over a six-month period. A randomized controlled trial was conducted, with 120 participants randomly allocated into an intervention group (n=60) and a control group (n=60). The intervention included weekly sessions of social skills training delivered by trained educators over six months. Pre- and post-intervention assessments were used to measure changes in social skills. During the study, there was a statistically significant improvement in social skills scores from pre-test to post-test for the intervention group ($t(118) = 4.23$, $p < 0.05$; CI: [2.3%, 6.7%]), indicating an average increase of 5% in social interaction abilities. The results suggest that school-based mental health support significantly enhances social skills development among students with ASS, contributing to their overall socio-emotional well-being. Further research should explore the sustainability and scalability of this intervention model across different urban contexts. The findings could inform policy makers in developing targeted educational programmes for ASS students.