Six cultivars of radish (<i>Raphanus sativus</i>) were tested for their usefulness in radish cytokinin bioassay by the method of <i>Letham</i> (1971). The best cultivar was found to be 'Sopel Lodu' which responds well to both zeatin and 2iP over a wide range of concentrations. The fresh weight of cotyledons increased at most by 71.5% (if treated with zeatin) or 101.0% (if treated with 2iP) compared to untreated cotyledons. This cultivar is also sensitive to the partially purified cytokinin-like fraction isolated from the pine (<i>Pinus silvestris</i>) cambial region. The cultivar 'Sopel Lodu' is therefore proposed to be a suitable plant for cytokinin bioassays.