Paclobutrazol (PBZ) is a plant growth regulator and it is a type of triazole, which could stop the biosynthesis of growth and development hormone (gibberellin). PBZ is also used to decrease the canopy volume and increase the flowering strength of many crops like peach. PBZ can shorten the plant height, increase the stem diameter and number of leaves as well. PBZ could be also used to control flowers blooming and fruits set. PBZ efficiency in plant tissue cultures have been reported as one of the most important inhibitory substances, which slow growth and decrease the numbers of subcultures. Moreover, PBZ has been widely applied in vitro to reduce growth and induce flowering. On the other hand, a lot of studies confirmed the promoting effect of PBZ for plants tolerance/resistance to different abiotic/biotic stresses. However, more studies concerning the ecotoxicology of PBZ in different environmental compartments are still needed to be investigated. In addition, the impact of PBZ on cultivated plants under combined stresses like heat-drought or drought-salinity is still needed to examine.