Using fluorescent lamps with different colours of light for improvement in vivo propagation of hyacinths by leaf cuttings, was the aim of this experiment. Leaves of three hyacinth cultivars were taken from plants forced in glasshouse, they were rooted in peat in growing room under fluorescent lamps TLD 36W emitting different colours of light: white, blue, green, yellow and red. Light with quantum irradiance of 25 µmol·m^-2·s^-1 was applied for 12 hours per day. Under lamps with white, blue or red colour of light leaf cuttings formed adventitious roots in large number and the longest; their weight was the greatest under lamps with white colour of light. There was no effect of the colour of light on number of adventitious bulbs developed on the leaf cuttings of cultivars ‘Anna Marie’ and ‘Blue Star’. In the cultivar ‘White Pearl’ the greatest number of bulbs was created under white, blue and green colour of light. However, a favourable effect on quality of bulbs was observed. The biggest bulbs with the greatest weight were formed under lamps emitting white and blue colour of light.

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