Noise immunity is becoming one of the most important design parameters for deep-sub-micron (DSM) technologies. Asynchronous circuits seem to be a good candidate to alleviate the problems originatedby simultaneousswitching noise. However, they are also more sensitive than synchronous ones to spurious signal transitions and delay variations produced by crosstalk noise. This paper addresses the problem of analyzing and synthesizing asynchronous circuits with noise immunity being the main design parameter. The techniques presented in the paper focus on cross talk noise and tackle the problem from the behavioral point of view.