Nanowhiskers are grown in a non-preferential growth direction by regulation of nucleation conditions to inhibit growth in a preferential direction. In a preferred implementation, III-V semiconductor nanowhiskers are grown on an (001) III-V semiconductor substrate surface by effectively inhibiting growth in the preferential B direction. As one example, InP nano-wires were grown by metal-organic vapor phase epitaxy directly on (001) InP substrates. Characterization by scanning electron microscopy and transmission electron microscopy revealed wires with nearly square cross sections and a perfect zincblende crystalline structure that is free of stacking faults.