The aim of the trial was to determine whether growth regulators and injuries could affect sex expression in the cultivated kiwifruit. Growth substances (NAA, BAP, GA, ethephon, ABA, TIBA, and CCC) were applied at 1% concentration in lanolin (w/w) to shoots of 17-year old plants of the staminate clone Matua and the pistillate clone Hayward. Injuries consisted in shoot defoliation or removal of a ring of phloematic tissue from the laterals. Both the application of growth regulators and injuries were done about 5 weeks before anthesis. In the pistillate clone, no treatment resulted in overcoming pollen grain sterility; ABA and GA increased the stigma-style number as well as the density of papillae on the stigma surface. A positive correlation was found between stigma-style number and pedicel length (r = 0.660). In the staminate clone, pollen grain viability was significantly altered by treatment; the highest (79.2%) and lowest (10.3%) values were recorded for ABA and GA, respectively. A negative correlation was found between pollen grain viability and pedicel length (r--0.648). As a general rule, treatments which depressed pollen grain viability allowed the development of a variable number of styles. About 20 styles were consistently produced when GA was applied; the gibberellin-caused feminization of kiwifruit was confirmed in a repeated trial. The data collected also suggest that sex expression can be slightly changed by injuries; contrariwise, rather good results can be achieved by using a growth regulator earlier in the season or before flower initiation.