Abstract The limiting 〈21̄1̄〉 and 〈2̄11〉 growth velocities have been measured as a function of melt undercooling for InSb dendrites containing two twin planes. From analysis of the data using a layer flow model, it is found that the kinetic rate constant for the interface is greater than 3 cm sec°C and that the effective interfacial energy is small, of the order of or less than 50 ergs cm 2 . It is shown that InSb freezing kinetics are probably slower than those of Ge. The envelope of decanted solid-liquid interfaces is asymmetric, an effect probably related to the anisotropy of kinetics induced by the polarity of the lattice; there is also a tendency for preferential formation of “Sb” facets. Experiments on growth from non-stoichiometric melts are reported, as well as the negative results of attempts to grow continuous dendrites in directions other than 〈21̄1̄〉 or 〈2̄11〉. Comparisons are made with the dendritic growth of Ge.