Background: Typical autism characteristics of rigid thinking, resistance to change and sensory processing difficulties make feeding problems common. Food selectivity can be one of the biggest challenges in caring for a patient with autism; selectivity with foods can lead to potential alterations in micronutrient intake.

Aim: To assess nutritional status, deficiencies and feeding behavior problems in children with autism spectrum disorder.

Patients and methods: A cross-sectional study carried out from 1^st of September 2023 to 31^st of December 2023 in autism center in children welfare teaching hospital in Baghdad. The study was carried on 80 participants their age group ranges from (>3year to <11 year). All participants underwent anthropometric measurements, dietary and biochemical assessment, and detailed questionnaire about feeding and mealtime behavior problems

Results: Fifty percent of children had normal BMI, 17.5% were classified as underweight, 27.5%, 5% were classified as overweight, obese respectively. Vitamin D deficiency was observed in (91.25%), there is significant association between vitamin D level and nutritional status (p-value 0.022). There is significant correlation between behavioral problems when introducing new food items, position during feeding, food refusal, selection of food type and texture with nutritional status.