To investigate the role of neuroinflammation in the etiopathogenesis of autism spectrum disorder (ASD), we investigated the role of fractalkine and tumour necrosis factor alpha (TNF-α), which may be potential biomarkers for ASD. This study aimed to evaluate the serum levels of interleukin-1beta (IL-1β), interleukin-6 (IL-6), and high-sensitivity CRP (hs-CRP) and to investigate the relationship between fractalkine, TNF-α, IL-1β, IL-6, and hs-CRP and the severity of symptoms in ASD.