Two pot experiments were carried out during the summer of the growing season 1999 to study the effects of paclubutrazol (PBZ) on growth, photosynthetic pigment contents, endogenous phytohormone contents and leaf structure of maize plants stressed with NaCl, high temperature and drought condition as well as the effects of PBZ on the alleviation of the adverse effects of these stresses.                 Pre-soaking of maize grains in 100 ppm PBZ decreased plant growth expressed by shoot and root lengths, leaf area, endogenous auxins (IAA), gibberellin (GA₃) and abscisic acid (ABA) concentrations. Whereas, the number of roots, photosynthetic pigment contents and endogenous concentration of cytokinins were increased. On the other hand, all stress treatments decreased all the above mentioned parameters, but endogenous concentration of ABA was increased. Exposure to heat stress had more aggressive injury on plant growth than other types of stresses. Treaments with PBZ partially alleviated the adverse effects of stress treatments.                 Anatomically, PBZ increased leaf thickness, epidermal cell thickness, mesophyll tissue thickness, the main vascular bundle dimensions and its xylem and phloem thickness, but all the above mentioned parameters were decreased under stress treatments.                 Pre-soaking of maize grain in PBZ at 100 ppm is recommended for protection of maize plants from salinity, high temperature and drought conditions.