Several studies have tried to estimate the average cognitive ability level in Peru. The results oscillated between IQ 90 (Lynn & Vanhanen, 2002) and 85 (Lynn & Vanhanen, 2006, 2012). Moreover, regional studies conducted in the city of Lima and in the Andean mountains, not employed by Lynn and Vanhanen, showed a mean IQ of 90 (IQ 105 for children of middle SES, and IQ 87 for low SES) and IQ of 78 for students from Lima and the Andean mountains respectively. A new randomly selected sample composed of 1097 children (53.5% female), with mean age of 11.6. years (SD. = 0.4; 75% between 11.0 and 11.9. years) enrolled in 6th grade from 18 schools (58.9% public schools) located in Lima was assessed using the Standard Progressive Matrices of Raven test. The average IQ was estimated at 91. Considering the three regions in which Peru is divided, the IQ for the whole country was estimated at 84. In addition, this study verified that higher education of parents from lower SES compared to higher education of parents from higher SES had the greatest impact on the intelligence of their offspring.