Illegal immigrants in the United States (US) have long been a topic of debate for politicians and the public. Their logic is that they don't pay taxes; they add to taxpayer costs and consume funds in resources intended to assist citizens and legal immigrants (legal citizens). Therefore, they are perceived as a threat to the US economy. The true impact of illegal immigrants on the U.S. economy is discussed by debating the economic benefits and economic costs of these immigrants. The negative impacts, discussed first, concern the decrease in wage rates of low-skilled jobs for legal immigrants and citizens instigated by illegal immigrants, the social services such as education and healthcare that they use up and add to taxpayers. Thus, contrary to negative impacts, positive impacts reveal the benefits of low production costs, increased sales on the local market, generation of undocumented taxes, impact on growth and employment brought by illegal immigrants. These impacts, both negative and positive, are independently analyzed and compared with each other. The discussion shows a slight net positive impact on the US economy in contrast to the normal belief about illegal immigrants. Illegal Immigrants and the US Economy: Is It That Big of a Problem? The journey from a few cavemen to seven billion humans on this planet was characterized by the physical movement of Homo sapiens from one place to another, sometimes for thousands of kilometers, individually or in the form of flocks, either voluntarily or involuntarily. This act of leaving one's land and moving to another land with a reason is known as migration. The reason can be anything, for example a bet... half the card... a security and a low enough pay. They include picking fruit and vegetables, cleaning homes, hotels and offices, as well as agricultural and construction work. These jobs are not preferred by many working Americans, but they are certainly a necessity in society. Illegal immigrants have no choice but to accept these jobs for the little money they receive. Therefore, they play a vital role in carrying out these works. The bigger picture of low wages and, indeed, low production costs should be considered. As wage rates decline, the entire population benefits by paying low prices for construction, agricultural products, restaurant meals, and cleaning services. It is estimated that due to illegal immigrants the wealth of the average American has increased; although this increase is remarkably small and represents no more than 1% (Davidson, 2006).