SLC1A1, which encodes the neuronal and epithelial glutamate transporter, is a promising candidate gene for obsessive‐compulsive disorder (OCD). In this study, we conducted capillary electrophoresis single‐strand conformation polymorphism (CE‐SSCP) screen for all 12 identified exons, including all coding regions and ∼50 bp of flanking introns of the human SLC1A1 in 378 OCD‐affected individuals. Full sequencing was completed on samples that showed an aberrant SSCP tracing for identification of the underlying sequence variants. Our aim was to determine if there are differences in the frequencies of relatively common alleles, or rare functional alleles, in 378 OCD cases and 281 ethnically matched controls. We identified one nonsynonymous coding SNP (c.490A > G, T164A) and three synonymous coding SNP (c.81G > C, A27A; c.414A > G, T138T; c.1110T > C, T370T) in case samples. We found no statistical differences in genotype and allele frequencies of common cSNPs in SLC1A1 between the OCD cases and controls. The rare variant T164A was found only in one family. Further investigation of this variant is necessary to determine whether and how it is related to OCD. There was no other evidence of significant accumulation of deleterious coding mutations in SLC1A1 in the OCD cases. © 2009 Wiley‐Liss, Inc.