Regulations establishing mandatory sustainability reporting practices are proliferating around the world. The empirical evidence comparing sustainability reporting quality (SRQ) in the context of mandatory and voluntary institutional frameworks does not show consensus. Similarly, this occurs with studies addressing the effects of regulatory shocks on SRQ. Moreover, empirical evidence addressing SRQ in Latin American countries is scarce. To fill this gap, this study aims to explore the consequences of introducing new regulatory requirements for sustainability disclosure on SRQ of Peruvian companies. To reach that goal, 81 sustainability disclosure documents published between 2014 and 2016 by 27 companies included in the S&P/BVL Peru General Index of Lima’s Stock Exchange were analyzed using qualitative content analysis methods and adopting a multidimensional approach for SRQ evaluation. The findings show a constant improvement of SRQ regardless of the introduction of the new regulatory requirements. Furthermore, after the entry into force of new sustainability reporting obligations, the number of companies providing third-party independent assurance of the information contained in their sustainability disclosure documents decreases, suggesting that for the Peruvian case, regulatory requirements tend to discourage companies to invest in the credibility of their sustainability disclosure documents, and promote a symbolic application of sustainability disclosure standards. View Full-Text