Synchronic alternations involving similar types of consonant/consonant metathesis are examined in Faroese and Lithuanian from both formal and functional perspectives. It is argued that by taking into account speech perception-based phonotactic constraints, we are able to gain insight into why metathesis occurs. The proposed formal account of the process is of particular theoretical interest given the apparent opacity involving the interaction of metathesis and place assimilation in Faroese. While straightforward in a serial-based account, this type of opacity has posed a challenge to Optimality Theory requiring the inclusion of additional formal devices into the theory. As we show, however, by modifying one assumption concerning the realization of the sequence, this additional formal machinery is rendered unnecessary. Opacity involving Faroese metathesis turns out to be an artifact of a particular phonological analysis.