Background and Objective: Autistic spectral disorder (ASD) afflicts one out of every 88 children, a 78% increase in the past 10 years along with increasing lifestyle stresses. The Earlier studies suggests that ASD children had larger head circumferences (HC) and abnormalities in central brain structures often associated with autonomic control. As both growth hormone and Autonomic nervous system (ANS) has same site of central control by hypothalamus, therefore, aim of the study is to investigate coexistence of growth abnormality with ANS dysfunction in ASD children. Methodology: An observational CASE-CONTROL study, having 25 age - sex matched subjects (mean age 15 years) each was designed. The CASES satisfied the criteria of ASD according to DSM-IV. The CONTROLS clustered the normal healthy children. The HC, height and weight were measured with a measuring tape and weighing machine respectively. Postural change in blood pressure (BP) was measured with a sphygmomanometer using pediatric cuff. Results: Significantly higher HC (P = 0.0001), decreased weight (p=0.00002), decreased basal metabolic indices (BMI) (p=0.02) was found in CASE compared to CONTROL. Height did not differ significantly between groups (P = 0.49).ANOVA application confirms statistical significant variation between group. In both groups , following correlation coefficient were calculated between (1)recorded height-weight-BMI and respective standard 90th percentile values( CDC growth chart) (2) recorded supine BP and expected 90th percentile BP , according to respective age and height percentile (3)HC and BMI (4) BP and height-weight . All the measured correlations show decreased value in CASE then CONTROL. Interpretation: These findings infer the probable growth abnormality in ASD. The Flashing result of fall in systolic BP was seen on assuming the erect posture from supine position in CASES. This implies ANS dysfunction. Conclusion: The above result clearly suggests the coexistence of marked growth abnormality, with ANS dysfunction in ASD children.