According to international research, parental aggression is observed in school premises, and it usually has a negative impact on schools’ climate and on actors’ social interactions. Parental aggression in school premises is a phenomenon not sufficiently studied in Greece. The aim of the present study was to fill the bibliography gap and to examine the impact of parental aggression on teachers’ everyday school life and well-being. Thus, a quantitative study was conducted, and an explanatory correlational design was used for the collection and analysis of the research data. Our target population was primary school teachers. 156 primary school teachers in Attica participated in our research by filling in an original questionnaire of closed-ended questions. According to the findings of the research, parental aggression is clearly observed in school premises. Parental aggression affects students, it influences the emotional state of teachers and has a negative impact on their everyday school life and well-being. Although aggression can be harmful to all teachers, specific individual characteristics of teachers (such as gender, age, working experience) can magnify certain impacts of aggression.