This dissertation analyzes the influence of ridesourcing services in reducing passenger demand in Brazilian public transportation systems. This reduction brings challenges to system managers and has been occurring for several years, a period in which new transportation alternatives have emerged, such as transportation by apps. The international literature indicates that the relationship between public transport and transportation by apps is complex and depends on the local reality, and maybe a competitive or complementary relationship. This dissertation assumes that ridesourcing services have captured a portion of the demand for public transport without disregarding possible complementary relations. Moreover, as the new sanitary reality imposed by Covid-19 has brought significant impacts on urban mobility in general, we sought to understand what consequences the pandemic generates in this relationship. A case study was conducted with university students living in the Metropolitan Region of Recife during the pandemic. To meet the objective, a literature review was performed, seeking the influential factors in modal choices, considering public transport and transportation by apps. It was investigated how the transport choice process takes place from the perspective of discrete choice theory. The mathematical model chosen was a Logistic Regression, given the alignment with the theory considered. A questionnaire was distributed via the web through snowball sampling, and 404 valid responses were gathered. Statistical analyses were conducted in possession of the answers. The results indicate a reduction in the use of the two modes of transport during the pandemic. The main reason for using public transport went from study to work, while in transportation by the app, it is no longer leisure. Vehicle ownership decreases the chances of choice in both modes. Higher education, the availability of driving licenses, and higher income have reduced the chances of using public transportation. Having a formal job and studying face-to-face has positively influenced the choice of ridesourcing. Public transportation was the most cited as a substitute in case of unavailability of ridesourcing services and vice versa. In case transport by apps does not leave the user at the final destination, the preferred mode to complement the trip is public transport. Thus, it is possible to conclude that the effects are complex but strongly more competitive for the group and site studied.