Con el fin de detectar un indicador del inicio del brote puberal se correlacionaron los niveles sericos del IGF-I con la edad, el peso, la talla, el estadio de desarrollo esqueletico (Hagg y Taranger) y el de la maduracion sexual (Tanner y orquidiometria de Prader), se estudiaron 33 pacientes, 18 de sexo masculino y 15 de sexo femenino, entre los ocho y los once anos de edad; el criterio de inclusion fue el de ninos sanos con un estadio de maduracion sexual de Tanner I. La toma de muestras se realizo cada seis meses durante tres anos (2000-2002). La poblacion general, mestiza, con una edad promedio de 9,48 ± 0,65 anos, se ubico en los percentiles 25-50 para peso (29,17 ± 6,41 kg) y talla (131,5 ± 6,91 cm) y en el estadio I de la maduracion sexual. El 100% de la muestra tanto femenina como masculina se ubico en el estadio F del desarrollo esqueletico. No hubo diferencia, por sexo, con respecto a la concentracion serica del IGF-I (175,00 ± 77,06 en hombres y 175,80 ± 88,39 en mujeres), a pesar de lo cual en el sexo femenino se encontraron correlaciones, estadisticamente significativas, entre IGF-I y edad (r = 0,56, p = 0,031) y peso (r = 0,58, p = 0,023). Tanto en hombres como en mujeres se observaron correlaciones estadisticamente significativas entre la edad y el peso, la edad y la talla, y la talla y el peso. Los volumenes testiculares derechos e izquierdos presentaron correlacion con el peso (r = 0,60, p = 0,009; r = 0,55, p = 0,017, respectivamente) y con la talla (r = 0,53, p = 0,023; r = 0,51, p = 0,030, respectivamente). El volumen testicular derecho se correlaciono con el factor de crecimiento insulinoide (r 0,48, p = 0, 045). Finalmente, se observo correlacion entre ambos volumenes testiculares (r = 0,86, p = ABSTRACT. In order to detect indicators of the onset of the spurt of puberal growth, the IGF-I seric levels were correlated with the age, weight, height, skeletal maturity stage (Hagg and Taranger). Each of the variables were correlated; other variables were included in the study such as general development and sexual maturity (Tanner and, Prader). A total of 33 patients were studied: 18 male and 15 female, between 8 and 12 years. Healthy children in Tanner I sexual maturity stage was the research criterion for inclusion. Blood samples, hand wrist roentgenograms, and general development data were taken every six months during the course of three years (2000- 2002). The general population, mestizo, was 9.48 ± 0.65 years old average, it was in 25-50 percentile range for weight (29.17 ± 6.41 kg) and height (131.50 ± 6.91 cm). At the beginning of the study, the population was in Tanner I sexual maturity stage. There was no sexual difference, with respect to the IGF-I seric level concentration (175 ± 77.06 in boys, and 175.80 ± 88.39 in girls), even though, statistically significant correlations were found in females, between IGF-I and age (r = 0.56, p = 0.031), IGF-I and weight (r = 0.58, p = 0.023). In the boys and the girls, statistically significant correlations were found between age and weight, age and height and height and weight. In males, the right and left testis volumes showed statistically significant correlations with weight (r = 0.60, p = 0.009; r = 0.55, p = 0.017), and with height (r = 0.53, p = 0.023; r = 0.51, p= 0.030), respectively. Finally, statistically significant correlations were found between testis volumes (r = 0.86, p =