Drought is one of the main abiotic stress factor that limits plant growth and development. Drought stress effects on Borago officinalis L. (borage) plants in terms of physiological and antioxidant responses have been evaluated in this study. In parallel with this purpose, relative growth rate (RGR), leaf relative water content (RWC), osmotic potential, chlorophyll fluorescence (Fv/Fm), lipid peroxidation, hydrogen peroxide (H2O2) level, superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) activities were determined under drought treatment in a controlled greenhouse. RGR, RWC and osmotic potential were significantly decreased, while lipid peroxidation expressed thiobarbutiric acid reactive substances (TBARS) and H2O2 contents were increased under drought stress. On the other hand, significant increases in POX, CAT, APX and GR activities did not prevent the increase in lipid peroxidation. To the best of our knowledge, this is the first study conducted on the enzymatic antioxidants of the defense system of Borago officinalis L. under drought stress.