This study tests relationships between, on the one hand, field-saturated infiltration rate into the uppermost sloping soil layer (KfJ and field-saturated hydraulic conductivity in soil horizons (Kfsh) and, on the other hand, in situ determined macropore sizes in soil profile descriptions. It was carried out at six locations along a transect on'a slope with loamy soils. The macropores were classified into representative size indices based on pore diameters (Ptd) and pore areas (P,,). A strong relationship was found between Kf,i and P,,, and between Kfsh and Ptd. The approach is promising and the methodology could be further developed with the aim of generalizing the functional relationships, so that Kf, can be estimated in areas where soil survey databases contain information on pore size abundance but lack Kf, values.