Background: Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) are neurodevelopmental conditions that arise from a complex interplay of genetic, biological, and environmental factors. Essential metal elements (EMEs), including copper, zinc, iron, and calcium, support brain development, support neuronal communication, and maintain normal metabolic activity. Any increase or decrease in these elements may play a role in the development of ASD and ADHD.

Objectives: The study aimed to investigate the relationship between serum levels of zinc, copper, iron, and calcium with ASD and ADHD. Moreover, to compare these levels among children with ASD, ADHD, combined ASD plus ADHD, and healthy controls.

Methods: A case-control study was carried out at the College of Medicine, University of Baghdad, between March and September 2025. In total, 200 children aged 2–15 years were included and divided into four groups: Controls (n = 40), ADHD (n = 30), ASD (n = 57), and ASD + ADHD (n = 73). Five ml of venous blood from each child was dispensed into a gel tube to estimate zinc, copper, iron, and calcium. Assessment of inorganic elements zinc and copper was performed by Flam atomic absorption spectrometry (FAAS) while iron and calcium was performed by spectrophotometer.

Results: Serum zinc levels were significantly lower in all patient groups compared with the controls. Copper levels were significantly higher, particularly in the ADHD and ASD + ADHD groups. Serum calcium showed no significant differences among the groups. Serum iron levels were significantly reduced only in ADHD group.

Conclusion: Reduced zinc and iron levels, together with elevated copper, may contribute to neurodevelopmental disturbances in ASD and ADHD. Monitoring and correcting trace-element imbalance could support better clinical outcomes in affected children.