The metallic pollution is recognized being harmful to nervous system. the “Gharb” plain (area of our study) localized in the North-West of Morocco is one of the most important agricultural and industrial regions of the Kingdom. Unfortunately, it suffered from the increase of different polluting human activities, especially metallic ones, which expose the children, living in this region, to serious neurobehavioral problems.

Objective and aims: Evaluation of the general intelligence in urban, periurban and rural schooled children (aged 6 to 8 years) living in Gharb plain and study of the relationship between the performance in this test and the quality of environment.

Raven's Standard Progressive Matrices (RSPM) and questionnaire about some environmental conditions.

The obtained results had shown that the best scores of RSPM was registered in the urban children (p < 0.01) and that was significant correlations between the performance in this test and the living zone (p < 0.001), the construction made material (p < 0.01), the source of pollution near the school (p < 0.001) and the consumption of well water (p < 0.01).

The children's intelligence appeared in connection with environmental factors, but a deeper investigation is needed for studying all these factors, in addition to others (psychological, socio-economical, and nutritional ones).