- Dimensionality and size are two factors that govern the properties of semiconductor nanostructures1,2. In nanocrystals, dimensionality is manifested by the control of shape, which presents a key challenge for synthesis3,4,5. So far, the growth of rod-shaped nanocrystals using a surfactant-controlled growth mode, has been limited to semiconductors with wurtzite crystal structures, such as CdSe (ref. 3). Here, we report on a general method for the growth of soluble nanorods applied to semiconductors with the zinc-blende cubic lattice structure. InAs quantum rods with controlled lengths and diameters were synthesized using the solution–liquid–solid mechanism6 with gold nanocrystals as catalysts7. This provides an unexpected link between two successful strategies for growing high-quality nanomaterials, the vapour–liquid–solid approach for growing nanowires8,9,10,11,12, and the colloidal approach for synthesizing soluble nanocrystals13,14,15. The rods exhibit both length- and shape-dependent optical properties, manifested in a red-shift of the bandgap with increased length, and in the observation of polarized emission covering the near-infrared spectral range relevant for telecommunications devices16,17.