Background: The work environment of nurses is characterized by high levels of stress and emotional tension. Nurses frequently experience aggression, considered one of the main occupational hazards in healthcare. The study aimed to identify causes, motivations, and factors influencing aggression towards young nurses. Material and Methods: The study involved 105 nurses from hospitals in the Silesian region of Poland, recruited via social media, with ≤5 years of professional experience. Conducted from January 18 to May 30, 2023, it used a proprietary questionnaire of 21 questions about the frequency, types, and causes of aggression experienced at work. Results: All nurses (100%) reported experiencing aggression in the workplace, mainly from colleagues (41.90%) and patients (34.29%). The most common forms were shouting (33.33%) and verbal abuse (31.43%). Adultism, defined as discrimination based on age or short tenure, was reported by 72.38% of nurses. Those experiencing adultism were more likely to report aggression from senior nurses (57.58% vs. 15.38%), but less likely to report aggression from patients (25.76% vs. 48.72%, p = 0.004). Although the association between unit type and level of adultism did not reach statistical significance (χ² = 5.555, p = 0.063), the data suggest a trend toward higher levels of adultism in certain units, particularly intensive care units which warrants further investigation. Nurses experiencing adultism reported lower job satisfaction (51.52% vs. 82.05%, p = 0.004) and were more likely to consider changing jobs (71.43%) highlighting the impact of adultism on professional relationships, job satisfaction, and overall well-being. Conclusions: Early-career nurses frequently encounter workplace aggression, primarily in the form of horizontal aggression associated with adultism and stress, which significantly reduces their job satisfaction. The most commonly reported forms of aggression include workplace obstruction, lack of support, insults, and shouting. Implementing conflict management training, psychological support programs, and mentoring initiatives can substantially improve working conditions and reduce staff turnover. Med Pr Work Health Saf. 2025;76(2)