<p>This study aimed to investigate a possible link between pets and siblings agression. For this, we constituted a sample of 330 university students, aged between 18 and 44 years, 61.2% female and 38.8% male, and we used the following instruments: a sociodemographic questionnaire, the LAPS (Lexington Pets Attachment Scale) and ESA (Scale of Experiences of Aggression between siblings). As expected, there were statistically significant differences with regard to sex, both in the relationship with pets, and in the experiences of aggression between siblings, and in the relationship with pets the female gender prevails, and the opposite happens in the experiences of aggression between siblings, where the male sex is more prevalent. The results suggest that the experiences of aggression between siblings are negatively associated with the bond and the importance given to the relationship with pets, and also point out that the bond with pets negatively predicts aggression between siblings. Generically, this study suggests that weak relationships in the fraternity may be one of the reasons for people to establish relationships with pets, possibly to seek comfort and companionship that they do not find in the family.</p>