Both derived from tryptophan, melatonin (MEL) and indole acetic acid (IAA) were tested for their influence on rooting in the cuttings of two Vitis species, the 5BB rootstock and the cultivar Cabernet Sauvignon. The 2-bud cuttings were grown in a growth chamber after the basal ends were dipped in the following treatments; for 5 seconds in IAA solutions at 0 (the control), 5.7, 11.4 and 16.1 mu M concentrations, and for 10 minutes in the melatonin solutions at 0 (the control), 0.1, 0.5 and 1.0 mu M. The results indicated that percentages of rooting, shooting and healthy plants in both species were not statistically significant under the influence of the treatments. However, increasing concentrations of IAA resulted in increasing rooting percentages in 5BB rootstock. On the other hand, 0.1 and 0.5 mu M MEL also induced rooting. In the cuttings of Cabernet Sauvignon, 11.4 mu M IAA provided the highest percentage (100%). Melatonin caused a relative decrease in rooting compared to the IAA. The action of melatonin on rooting seems to be independent of IAA. Hormone treatments caused significant differences in the root number per cutting and fresh root weight in 5BB. Effects of the hormones were important on all the rooting features, including root number, root length, root distribution pattern, and weight of fresh and dry roots in Cabernet Sauvignon. Results indicate that extensive research is needed to extrapolate the influence of melatonin on rooting in grapevine with a possibility in practical use since it is inexpensive and easy to obtain in pure form.