The influence of the specific Descolea antárctica {Da) and the non-specific Pisolithus tinctorious {Pt) ectomycorrhizal fungi on some physiological leaf parameters of the Chilean evergreen Nothofagus dombeyi subjected to a low soil water potential (-1.6 to -1.9 MPa in a growth chamber for 35 days) and a high water potential (-0.07 to -0.09 MPa, control) was studied. Drought decreased the water status and increased carbohydrates in mycorrhizal and non-mycorrhizal plants, appearing Z)a-mycorrhizal and non mycorrhizal plants better osmotically adjusted (OA= 0.60 MPa and 0.52 MPa, respectively) than ft-mycorrhizal (0.39 MPa). Proline is not involved in the O A of mycorrhizal plants. The inoculation of N. dombeyi with both ectomycorrhizal fungi favored a better maintenance of the functionality of the photosynthetic apparatus under drought as indicated by the effective quantum yield (cPPSII). It is concluded that both ectomycorrhizal and non-mycorrhizal N. dombeyi plants responded to water deficit with O A adjustment, having Z)a-mycorrhizal plants a greater O A than Pt- mycorrhizal plants