Nowadays pandemic caused by COVID-19 is affecting many aspects of the economic activity. The financial situation of many individuals and companies is in serious danger with important difficulties in fulfilling their contractual obligations. The question is whether there are remedies in the legal system to deal with this situation, such as the adaptation of the contract or the termination on the basis of the so called in Spanish Law the doctrine of the ?rebus sic stantibus? clause, that has its equivalent in other legal systems in the realm of Comparative law, under other terminology. European countries that have recently modernized their Civil Codes have reserved a special place for this type of legal institution. Today?s reality shows that our modern societies are not exempt from the risk of the emergence of unpredictable and extraordinary elements that can profoundly affect the economy. The standardised application of that legal institution by the courts, with the creation of rigorous case-law body, would contribute to a higher level of legal certainty as well as the reduction of transaction costs in the drafting of long-term contracts.