Objective: This study examined differences in cognitive functioning between English-speaking participants from a metropolitan area and Spanish-speaking participants from a rural migrant farming community using English and Spanish versions of the Lebby-Asbell Neurocognitive Screening Examinations for Children (LANSE-C) and Adolescents (LANSE-A), respectively. Our primary objective was to identify baseline performance differences between these two normative populations. A clear understanding of cultural influences on performance is critical to the assessment, intervention, and treatment of diverse populations. Method: The LANSE-C/A are clinical screening instruments with fourteen subtests assessing neurocognitive functioning. This study utilized archival data from 273 participants between 6 and 17 years. Subtest performance scores were used as predictor variables. A two-group discriminant function analysis was performed for the English-speaking (n = 63) and Spanish-speaking (n = 58) child group, and the English-speaking (n = 110) and Spanish-speaking (n = 42) adolescent group. Results: Discriminant functions derived from the analyses accounted for a statistically significant percentage of between-group differences in both the child [Wilks'Λ = .253, χ2 (3, N = 121) = 153.79, p< .001, R2c = .746] and adolescent [Wilks'Λ = .287, χ2 (3, N = 152) = 178.52, p< .001, R2c = .712] groups. Using a leave-one-out cross-validation strategy 94.2% and 91.4% of cases were correctly classified, respectively. Conclusion: Clinical implications of these findings emphasize caution in assessing neurocognitive functioning of diverse populations, due to differences in baseline performance. To prevent Type I errors or false positives, the clinician should consider the impact of cultural differences on normal baseline performance.