Background: Administration of quality care in the aged people requires having a positive attitude toward them. Numerous factors including nurses' personality characteristics may play a role in their attitude toward the aged people. Therefore, the present study investigated the association between nurses' personality characteristics and their attitude toward the aged people. Materials and Methods: This is a cross-sectional study conducted on 261 nurses selected through random stratified sampling. Kogan's Attitudes toward Older People Scale (KAOPS) was adopted to measure nurses' attitude toward the aged people, and five-factor personality inventory was used to detect their personality dimensions. The data were analyzed by descriptive and inferential statistical tests (Pearson correlation coefficient and multiple linear regression). P < 0.05 was considered significant. Results: Results showed that the predictive model of nurses' attitude toward aged people based on their five-factor personality dimensions was significant (P = 0.001). Overall, the variables, entered in the model, predicted 13% of variance of nurses' attitude toward aged people. Among the predicting variables, two dimensions of personality, including agreeableness (P = 0.046) and neuroticism (P = 0.003), significantly predicted nurses' attitude toward aged people. Conclusions: The results showed that nurses with higher agreeableness and lower neuroticism can be an appropriate option in caring for the aged people. Therefore, nurse managers are suggested to take steps toward creating a more positive attitude toward the aged people among nurses, in addition to holding educational programs for them with the goal of agreeableness empowerment.