PURPOSE: The COVID-19 pandemic has caused unprecedented changes in many areas of socio-economic life around the world. The unexpected situation forced the organizations to review the way they function and operate. The public sector was also faced with such threats, including the cultural sector, which is even more strongly required to rationally manage of public funds. The challenge for the managers of the cultural area was to achieve flexibility, which will allow for effective adaptation to changing conditions. The aim of the article is to present the assumptions of the effectuation theory as a method the use of which can determine the success of a cultural event in times of extraordinary danger. Effectuation thinking is seen as a way of dealing with an uncertain future, it is based on the control of resources, building open relationships with partners and turning unforeseen events into new possibilities. DESIGN/METHOD: This article presents the theoretical background regarding effectivity as a flexibility ensuring tool, which in turn is the key criterion of organizational effectiveness. Then the results of qualitative research based on a single case study were presented, in which an interview with the producer of the Lodz Four Cultures Festival, responsible for its organization during the ongoing coronavirus pandemic, was conducted. RESULTS/FINDINGS: This article presents the theoretical background regarding effectivity as a flexibility ensuring tool, which in turn is the key criterion of organizational effectiveness. Then the results of qualitative research based on a single case study were presented, in which an interview with the producer of the Lodz Four Cultures Festival, responsible for its organization during the ongoing coronavirus pandemic, was conducted. ORIGINALITY/VALUE: The effectuation theory, popular in entrepreneurship sciences around the world, has not been sufficiently discussed in polish literature. Using of the effectuation mechanism, as a tool of a public cultural sector management, is the scientific added value of this article. Presented in article analysis shows a potential for doing a further researches to verify, if the theory of effectuation had application in other cultural activity areas during a COVID-19 pandemic. KEYWORDS: effectuation, change, festival, pandemic, efficiency, adaptation. JEL: effectuation, change, festival, pandemic, efficiency, adaptation.