In the last decade, companies have started to disclose information on carbon emissions. To our knowledge, this is the first paper to look into this phenomenon in South America, which is a very important geographical area regarding climate change because of the local nature and developing economies. This paper explores the relationships between some corporate variables and two important decisions: (i) whether to report carbon emissions, and (ii) the impact on the evolution of carbon emissions. Logit and linear panel data models are used to determine the driving factors for decisions (i) and (ii). Our results show that regarding the carbon reporting decision, a company’s size, sustainability reporting, existence of a sustainability committee, and whether it belongs to a certain sector (telecom, utilities, and consumer discretionary) are significant positive factors, whereas the country is a negatively significant factor if the company is based in either Chile or Peru. Regarding the factors that lead to more sustainable behavior, our results reveal that a company’s size, the existence of a corporate social responsibility (CSR) committee, and the disclosure of a sustainability report lead to a decrease in emissions levels.