We have studied particle acceleration in different nanostructured targets irradiated by high intensity laser pulses of high contrast. We find that the maximum energy of emitted particles and their directionality is significantly enhanced in the case of nanostructured targets with respect to plane targets. We have studied theoretically in detail the generation and propagation of fast electrons in nanowire targets. Such targets exhibit an extraordinary high conversion efficiency of laser energy into electron kinetic energy. We observe guiding of electron bunches along the wires. Results from theory and simulation compare reasonably well with the experimental data.