This research aimed to determine the degree of online disclosure and dissemination of financial and non-financial information of the 66 most marketable companies listed in the Colombia Stock Exchange as of June 2013. For that purpose, 51 variables distributed in five types of information were configured: financial, corporate image, government and corporate structure, corporate and environmental responsibility, and access and browsability. Two measurements were taken with this: the first one investigates the degree of disclosure of each variable in all of the analyzed companies, and the second one associates such disclosure to the economic sector to which they belong. Results show that companies care about presenting their financial and corporate image information, particularly their portfolio of goods and services. In contrast, they do not significantly reveal voluntary aspects such as those relating to corporate and environmental responsibility. Similarly, it is concluded that the sectors of the economy that post the most information on their websites are the construction, hydrocarbons and financial sectors, while the ones that post the least are the food and energy sectors.