OBJECTIVE: To determine the association of learning and memory calcineurin binding (CABIN1) protein with autism spectrum disorders. STUDY DESIGN: Cross-sectional comparative study. PLACE AND DURATION OF STUDY: The Autism Research and Treatment Center, King Khalid University Hospital, Riyadh, Saudi Arabia, from October 2013 to May 2014. METHODOLOGY: Serum levels of CABIN1 protein in 62 (64%) autistic male children were analysed and 35 (36%) age healthy children measured by using ELISThe diagnosis of autism was made, based on the criteria of autism as defined in the DSM-IV. CARS (childhood autism rating scale) was used for the assessment of autistic severity. Data was analysed on SPSS version 21. Mann-Whitney U-test was used for comparisons of CABIN1 protein levels between the autistic and control groups at a p-value of <0.05. Spearman's correlation coefficient (r) was used to determine the relationships between different variables. RESULTS: There was no significant difference between the levels of CABIN1 between the 1.12 (0.01-8.8) pg/ml and healthy (1.51, 0.12-4.32) pg/ml in children. However, children with mild to moderate autism had higher CABIN1 protein level (1.27 pg/ml, 0.01-10.240) than children with severe autism (0.80 pg/ml, 0.01-4.25, p=0.145). In addition, there was no significant relationships among the serum level of CABIN1 protein, the CARS score, and age. CONCLUSION: CABIN1 protein level for children with autism was not significantly different from controls subjects as well as between children with mild to moderate and severe autism.