Treatment of topped radishes (Raphanus sativus L., cv. Cherry Belle) with methyl jasmonate was effective in inhibiting postharvest sprouting of new leaves and the growth of roots. Radishes were trimmed to 10-mm tops and dipped in various methyl jasmonate suspensions for 3 min. After storage at 15 °C for 7 days, the growths of new leaves were 26, 22, 7, 3, and 1 mm in 0, 10–5, 10–4, 10–3, or 2 × 10–3 M methyl jasmonate-treated radishes, respectively. The lengths of root growth were also reduced by methyl jasmonate particularly at higher concentrations. These treatments also substantially reduced weight loss possibly as a secondary effect. Fumigation with methyl jasmonate vapor in enclosed containers was also effective in inhibiting the sprouting of leaves and root growth, but to a lesser extent than dipping treatments. Radishes stored at 0 °C did not show any new growth of leaves or roots, and therefore were not affected by the methyl jasmonate treatments.