The effect of temporary drought on growth, carbon exchange and solute accumulation has been examined in alfalfa plants dependent on either N 2 or nitrate. Plants were subjected to cyclical moderate or severe drought (drought/recovery). Growth parameters, photosynthetic rate (P n ), leaf conductance to water vapour (g w ), chlorophyll content, and solute accumulation were determined. Growth decreased markedly under water deficit, but no significant differences between either groups of plants were found. Nitrogen-fixing plants developed higher root ratios maintaining larger leaves with increased specific leaf area and greater chlorophyll content than nitrate-fed ones. Leaf conductance and net photosynthetic rate declined simultaneously with the drought treatments in both groups of plants; however, N 2 fixing plants retained higher P n and g w values than nitrate-fed plants at lower RWC. Upon rewatering, a considerable stomatal closure remained in nitrate-fed plants. Drought treatment induced an increase in solute concentrations, mainly potassium, especially important in nitrate-fed plants. The interactions between the type of N nutrition and drought tolerance in alfalfa plants during temporary drought are discussed.