In the 1989/90 season 6‐year‐old Lincoln‐canopy trained ‘Nijisseiki’ and ‘Hosui’ Asian pear (Pyrus pyrifoliaNakai) trees were part‐tree sprayed with 400 ppm ethephon ((2‐chloroethyl)phosphonic acid), applied 15 days after full bloom (DAFB) or hand thinned (leaving one fruitlet at each fruiting site 56 DAFB) in a split‐plot design with ethephon applied to main plots and hand thinning to subplots. Ethephon reduced fruit set of ‘Nijisseiki’ and ‘Hosui’ by 37 and 15%, respectively, removing on average one ‘Nijisseiki’ fruitlet per cluster. Independently of hand thinning, ethephon reduced mean fruit weight of ‘Hosui’ at harvest by 34 g (21%), but ‘Nijisseiki’ was unaffected. Hand thinning increased fruit weight of ‘Nijisseiki’ and ‘Hosui’ at harvest by 19 g each (25 and 13%, respectively), only in the absence of ethephon application. Ethephon and hand thinning each increased return bloom of ‘Nijisseiki’ whereas only hand thinning increased return bloom of ‘Hosui’. In the same season, a whole‐tree spray of ethephon (400 ppm applied 15 DAFB) increased fruit set of ‘Doyenne du Cornice’ European pears (Pyrus communisL.) by 51%. In the 1990/91 season, ethephon applied at 400 ppm 15 DAFB reduced fruit set and fruit weight at harvest, and increased the incidence and severity of flesh spot decay of ‘Nijisseiki’ fruit, when assessed after 12 weeks of storage at 2°C. Ethephon also increased return bloom. In contrast naphthaleneacetic acid (NAA) (7.5 ppm, 15 DAFB) had no effect on fruit set or fruit weight, but reduced flesh firmness at harvest by 1.96 N (6%). In a second experiment in 1990/91 ethephon was foliage applied to Lincoln‐canopy trained ‘Nijisseiki’ trees 15 DAFB at 0, 200, 400, 600, or 800 ppm a.i. Fruit set was significantly reduced in proportion to the ethephon concentration with 800 ppm reducing fruit set by 62% compared to the nil treatment. Increasing ethephon concentrations significantly decreased mean fruit weight and flesh firmness at harvest, and significantly increased fruit soluble solids concentration and seed number. The incidence and severity of the fruit disorder, flesh spot decay, increased significantly in proportion to the concentration of ethephon when assessed after 12 weeks of storage at 2°C. Ethephon at both 600 and 800 ppm increased the area of individual spur leaves whereas neither shoot leaf nor spur leaf number were affected. Specific leaf weight (mg/ cm2) was increased irrespective of ethephon concentration. Ethephon significantly increased return bloom the year after treatment by an average of 52%.