Mobbing is characterized by the repetition, over a long period of time, of hostile behavior and unethical conduct carried out by a hierarchical superior or co-worker, against someone’s physic and mental integrity, endangering one’s job or disturbing the work environment. This current investigative study intends to assess the existence, frequency, and intensity of mobbing within the Portuguese nurse population, as well as its impact on their well-being and interpersonal relationships. The study carried out was quantitative, correlational, and cross-sectional. A questionnaire was used as the form to collect data. The questionnaire was sent out to 11 institutions in Portugal which were chosen at random, and it was also made available on a website for whoever wished to respond. The sample was composed of 3,227 nurses from various health institutions in Portugal. From the results obtained it was observed that on average each nurse undergoes 11 aggression conducts in their main place of work. The types of aggression suffered with greater intensity by the victims are communication blockage and being discredited at work. The predominant types of mobbing are the horizontal and the descending type. Nurses suspected the following motivations for those who had perpetrated mobbing against them: envy or jealous, not yielding or having been influenced by blackmail, not being subservient and being innovative, or entrepreneurial in the new work methods or perspectives. Almost half of the victims claim to have had health problems as a result of having suffered mobbing in their workplace.