Autism spectrum disorder (ASD) is a pervasive broad-spectrum disorder that involves multifaceted delays in the development of many basic, social, and communication skills. The etiology of ASD is multifactorial and involves interplay among genetic, neurologic, hormonal, metabolic, immune-inflammatory, and environmental factors; which further complicate both the diagnosis and management in affected individuals. This review delineates the underpinnings of clinical challenges posed by ASD, like clinical heterogeneity of patient presentation, unresolved ASD genomic map and deficient drug therapy. Besides, it addresses the emerging pathogenic, etiologic, and diagnostic clues of diverse origins, encompassing genetic-, neurotransmitter-, androgenic-and immunoinflammatory-anomalies in ASD patients, as availed by advances in Omics technologies (like genomics and proteomics). Moreover, as unravelled by metabolomics studies, metabolic flaws that pertain to amino acids, fatty acids, mitochondrial anomalies, and oxidative-stress are highlighted and further correlated with the extent of clinical picture and malbehaviors coherent with ASD patients. Lastly, future directions are underlined to promote and rationalize ASD research so as to help translate its findings into remedy.