A procedure to identify in the system parameter plane the critical ignition conditions and the parametrically sensitive regions for reactors with reverse-flow operation is developed. This is based can the generalized criterion for parametric sensitivity, originally developed by Morbidelli and Varma (1988, Chemical Engineering Science, 43, 91-102). In particular, the steady-state solid phase temperature maximum, established after a sufficiently long operation, is chosen as the objective for the sensitivity analysis. The critical ignition condition and the parametrically sensitive legion are defined as the situations where the normalized objective sensitivity with respect to variations of any of the system parameters, reaches its maximum or minimum. Maps of the critical ignition and parametrically sensitive regions are presented and the influence of various reactor operating parameters is investigated. These results can be used to find correct ignition and operating conditions for reactors with reverse flow in the early stages of reactor design.