Abstract.The gravitropic curvature of primary maize rootlets was measured as a function of temperature, both in the presence and absence of light. In two different cultivars, light strongly increased the downward curvature of roots developing from horizontally‐oriented embryos. At 15–20°C, the bending angle was in the range of 70–80° in the light, and 25–50° in the dark, depending on the cultivar. When the temperature was increased above the 15–20°C range, marked differences were found between the two cultivars in their response to light. In one variety tested, JX180, the effect of light was relatively small at 30–35°C. Gravitropic curvature in another variety, Halamish, depended strongly on light throughout the temperature range tested. In both cultivars, gravitropic curvature was only slightly temperature dependent when germination and growth were in total darkness. In the dark, the extent of gravitropic curvature also depended on whether the kernels were oriented with their embryos facing upwards or downwards. Under continuous light, the gravitropic bending of roots of cultivar Halamish did not show a marked temperature dependence. When the seedlings were subjected to only a 15 min illumination, their gravitropic response was partial, and the dependence on temperature somewhat increased. In cultivar JX180, a combination of temperature and light modulates gravitropism. The gravitropic response of different maize cultivars thus differs considerably in its combined dependence on light