The purpose of this study was to explore the effects of acculturation on the parent and teacher ratings of non-clinical Mexican American children's behavior, using the BASC Parent Rating Scale-C (PRS-C ) and the Teacher Rating Scale-C (TRS-C ). One hundred twenty-three children of Mexican descent (ages 6-11) attending Texas public schools were rated by their parents and teachers. Parent acculturation level was measured using the Acculturation Rating Scale for Mexican Americans-II. Parents were assigned to High, Medium or Low acculturation groups based on a combination of linear acculturation levels (Part 1) and obtained typologies (Part 2). Parent acculturation level was then assigned to TRS-C data creating matched-rater pairs (PRS-C and TRS-C of same child) for use in this study. Internal consistency reliabilities for the Total Mexican American sample's Teacher Rating Scale-C (TRS-C) were more similar to the published BASC general norms than the Total Mexican American sample's Parent Rating Scale-C (PRS-C ) on six of the nine clinical scales investigated and on all three of the shared adaptive scales. The most striking internal consistency result emerged when the sample was subdivided by acculturation, the High acculturation TRS-C Conduct Problems scale showed no cohesion of items for this sample (.00). Comparison of the Total, High, Medium, and Low groups' obtained distributions on each of the 16 selected scales of the PRS-C and TRS-C to the published BASC general norms revealed: 1) six significant differences of potential clinical relevance on the PRS-C scales, and 2) thirteen significant differences of potential clinical relevance on the TRS-C scales. Both parents and teachers rated the children as demonstrating less maladaptive symptoms on the Aggression, Depression, Hyperactivity, and Behavioral Symptom Index. Only parents reported lower Adaptability and Adaptive Skills scores. And only teachers of the High acculturation group reported higher Adaptability scores. No systematic influence of acculturation was present among any of the 16 selected scales. However, the parents and teachers of the High acculturation subgroup did have more moderate correlations than the Medium and Low groups combined.