This paper aims to explain the effects of immigration on the overall crime rate and in the six most significant categories of crime in Saudi Arabia, being drugs activity, theft, murder, assault, alcohol and outrageous issues, during a ten-year period from 2003 to 2012, in all thirteen administrative provinces, as well as establish the provinces most affected by criminal activities of immigrants during this period. In our finding, no positive association between immigrants and criminal cases was noted. It is clearly visible that the highest rate of overall criminal activities is in the south, north and Makkah areas, where there is high probability of illegal immigrants, supporting the basic criminological theory that areas with high levels of immigrants also experience high rates of crime. The study provides suggestions to the Saudi government, policy and decision makers, and immigration authorities, which could assist in reducing crimes perpetrated by immigrants.