The consequent effect of growth retardants: paclobutrazol – 0.1, 0.5, 1, 5 mg l^-1, flurprimidol – 0.1, 1, 5 mg l^-1, chlorocholine chloride (CCC) –5, 50 mg l^-1 on the growth and development of Tibouchina urvilleana Cogn. in vitro was examined. Paclobutrazol at concentration of 1 or 5 mg l^-1 and flurprimidol at 5 mg l^-1 inhibited the growth of shoots significantly. It was noted that shoots originating from these media had thicker, straighter stems and shorter internodes. The stimulating influence of CCC at 5 mg l^-1 on the elongation of the main shoot was observed. Axillary shoots formation was the best when shoots were derived from the medium supplemented with flurprimidol 1 mg l^-1. Paclobutrazol at 0.5 and 1 mg l^-1 and flurprimidol at 5 mg l^-1 influenced the formation and fresh weight of roots increase, but flurprimidol was more effective. Growth retardants (except paclobutrazol at 5 mg l^-1) applied in the earlier passage stimulated elongation of roots.

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