This paper develops novel procedures for designing of iterative learning control (ILC) schemes for both continuous-time and discrete-time systems. These procedures are developed by transforming the ILC design problem into stability problem for a two-dimensional (2D) system described by the Roesser model. Moreover, since the results are based on 2D system stability conditions that can reach necessity then the resulting design conditions are possibly characterized by a very low level of conservativeness. All conditions are derived in terms of linear matrix inequalities (LMIs), and they directly give formulas for computing the required ILC controllers. A numerical example to demonstrate the new results is also given.