The age range of the prepubertal developmental period in boys is between the age of 6 and 7 years resp. and the age of 12 (in girls between 6 and 10 years). The upper borderline of this interval displays, however, a considerable interindividual variability as regards the onset of puberty. Based on an analysis of 67 anthropomet- ric and functional parameters in a group of 763 healthy boys aged 7 to 13 years the author evaluated developmental correlations and trends typical for the period of prepuberty and the onset of the pubertal growth acceleration. It was confirmed that prepuberty is the period of relative developmental quiescence when the development of different somatic parameters is slow and proportional. An exception is to a certain extent only height and signs associated with it (length of the upper body segment, length of the lower extremity etc.) where at the age of cca 8 years a mild growth acceleration was found described as mid-growth spurt. A typical phenomenon of prepuberty in boys is a change in the subcutaneous fat distribution from the peripheral type to the centripetal one. This phenomenon can be recorded already from the age of 7 years, the general change of this ratio can be reliably confirmed however only after the age of 15 years. At the onset of the pubertal growth acceleration which in boys is on average between the age of 12 and 14 years the dynamics of growth of different somatic parameters increase again markedly.

        Key words: prepuberty, onset of puberty, boys, somatic growth and development, body composition, distribu-