We report on the magnetic structures in the TbPd1-xNixAl compounds as determined by powder neutron diffraction. The development of magnetic structures in the Tb(Pd,Ni)Al series is relatively simple. All the compounds show the existence of two magnetic phases with almost unchanged Neel temperature K and an additional magnetic phase transition temperature K. The arrangement of the Tb moments between TN and T1 is identical for all the concentrations and is characterized by a () propagation vector with one-third of Tb moments frustrated to nearly zero. Certain concentration development occurs only below T1. Magnetic moments that are frustrated between TN and T1 change their propagation below T1 to commensurate () or incommensurate (), depending on the Ni concentration. The magnetic moments stay parallel to the hexagonal c axis for all concentrations and temperatures.