Primary mitochondrial disease and secondary mitochondria disorders have received increasing recognition in the medical world. In fact, mitochondrial dysfunction plays a significant role in many common illnesses such as diabetes, obesity, cancer and heart disease, as well as neurologic and psychiatric conditions. Yet less is known about the optimal treatment for mitochondrial disorders. Given the scarcity of clinical research, current treatment is mostly based on expert opinions, preclinical trials and animal models. Autism spectrum disorder (ASD) is a neurological and developmental condition that manifests in divergent behaviours affecting learning, communication and social engagement. Recent research suggests that there may be a link between mitochondrial abnormalities and ASD. About half of children with ASD display measurable biomarkers indicative of mitochondrial dysfunction, and the prevalence of primary mitochondrial disorders is much higher in children with ASD compared to those without ASD presentation. Several mitochondrial co-factors are supplemented in the management of mitochondria disease and also have shown promising effects on ASD symptoms. Hence this observational study sought to explore the impact of such substances on mitochondrial function in children with ASD. The project involved 127 children with ASD, some subjects were on specific mitochondrial supplements and some also had a diagnosed mitochondrial disease. The activity of mitochondrial metabolism was assessed at several stages, via a salivary mouth swab. Results from this study suggested that several common mitochondrial supplements such as fatty acids, antioxidants, B12 and folate influence mitochondrial function. However, some of these influences were more pronounced or in some cases limited to the subgroup that also had prevailing mitochondrial disease. The findings affirm that these interventions improve mitochondrial function and maybe be most effective in ASD cases with underlying metabolic disorders.