The novel highly transmissible human coronavirus SARS-CoV-2 is the causative agent of the COVID-19 pandemic. Thus far, there is no approved therapeutic drug specifically targeting this emerging virus. The aim of our work was to isolate and characterize a panel of human neutralizing monoclonal antibodies targeting the SARS-CoV-2 receptor binding domain (RBD). Peripheral circulatory lymphocytes were collected from patients during the acute phase of the disease. These were used as the basis of an antibody phage display library, from which highly neutralizing antibodies were isolated. These anti-SARS-CoV-2 antibodies recognize distinct epitopes on the viral spike RBD. A subset of these antibodies exert their inhibitory activity by abrogating binding of the RBD to the human ACE2 receptor. Taken together, our findings suggest that these antibodies might serve as an efficient treatment of COVID-19 patients or as a prophylactic immunization.