A field study and an experiment under controlled conditions using pressure-flux relationships were conducted to compare the stem and whole-plant conductance in olive (Olea europaea) and kiwifruit (Actinidia deliciosa) species. Anatomical observations were also made on one-year-old stem to determine the conductive area of vessels (A ves) and the total xylem area (A xyl). Results show that A ves of kiwifruit twigs was ~2.5-fold of that in olive twigs, and the hydraulically weighted mean diameter was up to threefold that of the olive ones. One-year-old olive twigs had lower hydraulic conductivity (k) than the kiwifruit, while values of leaf-specific conductivity (i.e. k normalised per unit leaf area) were higher than the kiwifruit (i.e. ~49 and 29 × 10−6 kg m−1 s−1 MPa−1, respectively). In the field experiment, the flux of sap (heat balance method) and differences in water potential through the soil–plant system (ΔP) were used for both species to calculate the whole-plant conductance that was normalised per unit leaf area (leaf-specific whole-plant conductance, K plant,LA). Values of K plant,LA are attributable to the combined effect of the ΔP and anatomical features of conduits. Olive species showed a larger ΔP (2.4 MPa at midday) than the kiwifruit (0.5 MPa) which contributed to lower K plant,LA in Olea than the Actinidia plants. This information, combined with vessel density data, contributes to explain differences amidst olive and kiwifruit species, in terms of susceptibility to some drought-related hydraulic impairments induced by the Mediterranean environment.