All summer-to-autumn-flowering chrysanthemum (Chrysanthemum morfolium Ramat) cultivars sprayed with 0.1–1.0 mg/l of 6-benzylaminopurine (6BAP) flowered 2.2–3.9 days earlier than controls, however, 6BAP at using 10 mg/l inhibited flowering. Stem lengths of all cultivars treated with 0.1–1.0 mg/l of 6BAP were as long as control values, however, those of plants sprayed with 10 mg/l were 11.2–15.1 cm shorter. Flowering in ‘Seiun’ and ‘Summer-yellow’ treated with 6BAP plus 200 mg/l of ethephon was the same as with 200 mg/l of ethephon only. Second lateral buds in the upper plant canopy of both cultivars grew after the disbudding of first lateral buds, upper leaf color lightened, leaves became large, and the hairs on the back of leaves grew when 10 mg/l of 6BAP with or without 200 mg/l ethephon was applied. © Pesticide Science Society of Japan