Abstarct: Background: Weight training is an important aspect of physical fitness, but it is associated with a significant risk of injuries. High training frequency, inadequate recovery, and pushing through fatigue are key risk factors for sports injuries among weight trainers, often driven by psychological factors like exercise addiction, obsessive passion, athletic identity, and Body Image. This study aims to identify demographic, training, and psychological risk factors, such as exercise addiction, passion for exercise, athletic identity, and Body Image, to inform strategies for reducing injury risk and promoting safer training practices among weight trainers. Methods: This nine-month observational prospective cohort study investigated injury risks among 381 weight trainers (mean age: 31.9 ± 8.6 years; height: 168.8 ± 9.6 cm; weight: 76.3 ± 19.8 kg; 62.2% women). Participants completed an online questionnaire capturing their demographics, training habits, coaching status, injury history, and psychological factors. Sports injuries were monitored biweekly from November 2023 to September 2024, with the primary outcome measured as the rate of injuries per 1,000 hours of training. Logistic regression with backward selection was used to analyze data, reporting odds ratios (OR) and 95% confidence intervals (CI) to identify significant predictors of injury risk. Results: Over the nine months, 22.05% of weight trainers sustained 157 injuries, with an incidence rate of 1.86 injuries per 1,000 training hours. The most commonly injured areas were the lower back (24.2%), shoulders and neck (20.38%), and knees (16.6%). Injury history, obsessive passion, exercise addiction and training with a partner were significant predictors of injury risk (χ²(3, N = 381) = 27.4, p = 0.001). Previous injuries increased the risk of new injuries by 3.74 times. Each unit increase in obsessive passion raised the injury risk by 73%, while each unit increase in exercise addiction increased the risk by 12%. Conversely, training with a partner reduced injury risk by 70%. Conclusions: Psychological factors, particularly obsessive passion and exercise addiction, significantly contribute to injury risk among weight trainers. Injury prevention strategies should address these factors and encourage safer practices, such as training with a partner, to reduce injury risk and promote long-term fitness.