When gold nanorods are exposed to low-energy laser pulses, they can undergo shape transitions at temperaturesbelow melting. In the present study such transitions are reproduced in molecular dynamics simulations ofgold nanorods consisting of 103−104 atoms. We find that the shape change is accompanied by a structuralchange. On the basis of the simulation results, a mechanism is suggested that explains the intermediate productsand the internal defects of gold nanorods observed in laser heating experiments.