Five black poplar (Populus nigra L.) genotypes were grown in a semi-controlled environment and were subjected to three different soil water regimes: control (90-70% of maximal field capacity-FC), drought followed by recovery of optimal soil water saturation (90-40% of FC) and permanent drought treatment (50-40% of FC). Variation in leaf gas exchange parameters such as photosynthetic (P) and transpiration intensity (T), as well as water use efficiency (WUE) were investigated among genotypes in their response to water deficit and recovery from drought. Recovery of soil water field capacity from 40% to 90% determined restored values of P, T and WUE. After 16 days of permanent drought (50-40% FC), strong decline of all parameters among examined genotypes was determined. Overall, significant differences among genotypes in leaf gas exchange parameters were found, which can give some indications of superiority of certain genotypes in relation to drought stress.