The aim of this study was to investigate iron deficiency anemia and Vitamin D deficiency among autism children and to assess the importance of risk factors (determinants). Subjects and Methods: This was a case-control study conducted among children suffering from autism at the Hamad Medical Corporation in Qatar. A total of 308 cases and equal number of controls were enrolled. The Autism Diagnostic Observation Schedule-Generic was the instrument used for diagnosis of Autism. Results: The mean age (+/- standard deviation, in years) for autistic versus control children was 5.39 +/- 1.66 versus 5.62 +/- 1.81, respectively. The mean value of serum iron levels in autistic children was severely reduced and significantly lower than in control children (74.13 +/- 21.61 mu g/dL with a median 74 in autistic children 87.59 +/- 23.36 mu g/dL in controls) (P = 0.003). Similarly, the study revealed that Vitamin D deficiency was considerably more common among autistic children (18.79 +/- 8.35 ng/mL) as compared to healthy children (22.18 +/- 9.00 ng/mL) (P = 0.004). Finally, mean values ofhemoglobin, ferritin, magnesium; potassium, calcium; phosphorous; glucose, alkaline phosphate, hematocrit, white blood cell, and mean corpuscular volume were all statistically significantly higher in healthy control children as compared to autistic children (P < 0.001). Multivariate logistic regression analysis revealed that serum iron deficiency, serum calcium levels, serum Vitamin I) levels; ferritin, reduced physical activity; child order, body mass index percentiles, and parental consanguinity can all be considered strong predictors and major factors associated with autism spectrum disorders. Conclusion: This study suggests that deficiency of iron and Vitamin D as well as anemia were more common in autistic compared to control children.