A system for positioning a row of photovoltaic solar panels (1) on a support structure (S) arranged in an outdoor space includes a vehicle (20) on which the photovoltaic solar panels (1) to be installed are arranged, and a manipulator robot (24) arranged on-board the vehicle (20) for sequentially picking-up one or more photovoltaic panels (1) from the vehicle, and for positioning them on said support structure (S) as the vehicle moves on one side along the support structure (S). An optoelectronic system (27) is used for automatic optical recognition of the correct position in which a photovoltaic solar panel (1) must be picked-up as well as the correct installing position of the photovoltaic solar panel (1) on the support structure (S).