Introduction. People breed animals, professionally take care of them, and work with them. To live with animals, however, it is necessary to know their behaviour and habits, as well as fears. Ignorance of this knowledge may lead to tragedy for the victim (a person), as well as for the beast (animal). Then, nobody cares whether the animal behaved itself or not in accordance with its nature. Objective. The aim of the presented study is to compare the rate of animal aggression in relation to cases of documented aggression towards humans. The victims were investigated according to the age, gender and types of injuries caused by animal bites. Material and methods. The protocols of autopsies (2,218) and medical-legal examinations (4,569) performed from 2004-2009 in the Department of Forensic Sciences in Poznań were analyzed. The selected data was studied using Microsoft Office Excel 2007 for Windows. Results. Analysis revealed the presence of animal bite injuries in less than 1% of the deceased victims of aggression. The number of individuals who died as a result of animal bites varied from 1-4 a year, and in all cases these were postmortem injuries. Analysis of injuries among surviving victims of aggression showed animal bite injuries were present in 41 out of 4,569 victims, almost equally among males and females. Moreover, in 25 victims the bite injuries recognized as human were found. The majority of animal bites occurred in adults. The medium injuries were the most frequent in the animal bite victims. Conclusions. Animal aggression is a marginal problem considering all cases of aggression towards humans. In contrast to the aggression of humans towards other humans, this is a very rare cause of human death or even major injury.