Abstract
Mediation as a popular method of ADR is more and more often used while solving cross border disputes. Although the mediation clauses are included into the commercial contracts almost automatically, no attention is paid to its validity, enforceability and other legal consequences. The article provides a study on the nature of mediation clauses that crucially influences the law governing validity of mediation clauses. It is the position of the author that mediation clauses are primary institutes of the substantive law and thus the governing law should be determined in accordance with the Rome I regulation.