In this paper we consider detection of faults in CMOS cells that are more complex than primitive gates. We derive a single set of tests based on functional description of the cells. The tests derived, if applied, detect multiple stuck-at faults, multiple transistor stuck-open faults, cross wire open faults, delay faults and bridging faults between inputs of the cell, in any implementation of the cell functions. We give results on an industrial design to demonstrate the benefits of the proposed tests relative to standard stuck-at, cell exhaustive and transition fault tests in covering faults in such cells.