This paper examines the connection between illegal migration, minimum wages and enforcement policy. We first explore the employers’ decision regarding the employment of illegal migrants in the presence of an effective minimum wage. We show that the employers’ decision depends on the wage gap between those of the legal and illegal workers and on the penalty for employing illegal workers. We consider the effects a change in the minimum wage has on the employment of illegal immigrants and local workers. We conclude by considering the optimal migration policy taking into consideration social welfare issues.