Objective: Despite the fact that there are close to 51 million of Spanish-speakers in the USA, an evident paucity of norms for testing bilingual Spanish/English children is observed. The aim of this study was to establish normative data for Spanish/English bilingual or Spanish monolingual pre-school children using a comprehensive Neuropsychological battery (Evaluación Neuropsicológica Infantil para Pre-Escolares). The Evaluation was developed in Spanish to assess a wide spectrum of cognitive functions (constructional and motor abilities, memory, delayed memory, perceptual abilities, oral language, spatial skills, attention, concept formation and executive functions). Method: The sample included 60 Spanish/English bilingual children born in the US to immigrant parents from Spanish speaking countries between the ages of 2 ½ and 5 years old. The children were tested using the Neuropsychological battery for pre-schoolers in three sessions, of one hour each, at their school. To validate the Neuropsychological battery, we used the McCarthy battery on 20 participants of the sample whom were also retested for test reliability. Results in this sample were compared with a monolingual Mexican sample matched by age and gender. Results: Significant differences were observed between the two samples on several neuropsychological tests. A significant age effect was observed in most tests. A non- significant gender effect was found. Conclusion(s): Findings are expected to be useful when testing other Spanish/English bilingual or Spanish monolingual pre-school children living in the USA.