tLongan (Dimocarpus longan) is a subtropical fruit tree with a long cultivation tradition in South East Asia,and also with a clear potential in other areas of the world. In other plant species, the reproductive phaseis most vulnerable to temperature conditions, but information on the effect of temperature on pollengermination and tube growth in longan is still lacking. In order to fill this gap, in this work the effect oftemperature on longan pollen germination was assessed both in vivo and in vitro. For this purpose firstpollen germination was evaluated in vivo at three temperature regimes, showing the best performanceat 23/24◦C. Then an in vitro pollen germination medium was optimized for longan and pollen storageconditions were evaluated, showing good pollen germination in vitro after storage for one year at −20◦C.Finally, the effect of temperature was evaluated in vitro in four cultivars and for two male flower typesM1 and M2, differing on the degree of pistil differentiation. Both pollen types behave similarly in allconditions, and all the cultivars studied had good pollen germination in vitro at 30◦C, a temperaturehigher than that reported as optimum in vivo reflecting a higher sensitivity of the stigma than pollento high temperatures. However, clear differences between cultivars in their performance at 20◦C and40◦C were recorded. These results set the basis for reproductive biology studies and breeding in longan,opening a window to select the best cultivars for different temperature conditions.© 2015 Elsevier B.V.