This study aims at revealing the key factors behind some moral crimes and how these factors are related to personal traits of prisoners in the Oman Central Jail. The study population consists of all moral crime prisoners in the central jail in Oman till the end of September 2011, with a total number of 108 prisoners. Using questionnaires, the researcher shortlisted the study sample to only 71 prisoners, 66% of the total study population. To achieve the objectives of the study, the researcher used two measuring tools, the first made by him and consists of 58 items to identify the key social, economic, cultural and psychological factors behind moral crimes. The second tool is McCrae's big five personality dimensions and it consists of 60 items. The study revealed the following: 1. The main economic factors behind moral crimes are: poverty, unemployment and women working in men's jobs. 2. There is a statistically significant negative correlation of (0.05 – 0.01) between the economic factors and the personality dimensions of Neuroticism, Agreeableness and Conscientiousness. 3. The main social factors behind moral crimes are: bad friends, misuse of free time, women's scandalous clothing, staring at women beyond the family circle and mixed gender places. B 4. There is a statistically significant negative correlation of (0.01) between social factors and personality dimensions of Neuroticism and Agreeableness. 5. The main cultural factors behind moral crimes are: alcohol drinking, weak faith in Allah, inappropriate sex education, low education levels, music addiction, song video clips and misuse of cellphones. 6. There is a statistically significant negative correlation of (0.05 – 0.01) between the cultural factors and the personal dimensions of neuroticism and agreeableness. 7. The main psychological factors behind moral crimes are: sexual needs and sexual deprivation. 8. There is a statistically significant negative correlation of (0.05 – 0.01) between the psychological factors and the the personality dimensions of neuroticism and agreeableness. 9. There are statistically significant demographic variables in the factors like the marital status, crime locations and type of the crime. The researcher has proposed some important steps to counter the problem, and recommended that academic studies should be conducted on the Islamic values and morals.