The study aimed to identify the level of psychological immunity and post-traumatic growth among a sample of students at the National University in the Sultanate of Oman; to investigate any differences that may exist in the levels of psychological immunity and post-traumatic growth according to the variables of gender, age and college. The study also aimed to reveal the extent to which psychological immunity contribute to predicting post-traumatic development. The reduced sample size of (354) male and female students from the National University was selected. To achieve the objectives of the study, the Psychological Immunity Scale and the Short Version of the Post-Traumatic Growth Scale were used, and the validity, reliability, and psychometric properties of the two scales were confirmed. The results of the study showed that the level of psychological immunity and post-traumatic growth among students were at an average level in general, and that there were statistically significant differences in the level of psychological immunity due to gender in favor of males, and statistically significant differences according to the variable of age and college in general. While the results of the study showed that there are no statistically significant differences in the level of post-traumatic growth due to the variables of gender, age, and college. The results of the study also revealed that psychological immunity contributes to predicting post-traumatic growth among the study sample. The study came out with a set of recommendations and suggestions in light of the findings that have been found.