The monoenergetic gamma-ray attenuation methodology is applied to study the structure of two well-aggregated Brazilian soils. The methodology distinguishes pores that comprise the space between aggregates and pores present only within aggregates. A comparison of the results with those obtained by conventional methodologies, indicates very good agreement. It is concluded that the methodology is very convenient to monitor the spatial distribution of inter- and intra-aggregate porosities since it is a nondestructive methodology and allows the evaluation of porosity changes that may occur during long periods of soil cultivation. Once having obtained a calibration regression for a given soil layer, total intra- and inter-aggregate porosities can be obtained from soil bulk density data only.