The Czech government has identified commercial health insurance as one of the major problems for migrants' access to health care. Non-EU immigrants are eligible for public health insurance only if they have employee status or permanent residency. The present study examined migrants' access to the public health insurance system in Czechia. A cross-sectional survey of 909 immigrants from Ukraine and Vietnam was conducted in March and May 2013, and binary logistic regression was applied in data analysis. Among immigrants entitled to Czech public health insurance due to permanent residency/asylum, 30% were out of the public health insurance system, and of those entitled by their employment status, 50% were out of the system. Migrants with a poor knowledge of the Czech language are more likely to remain excluded from the system of public health insurance. Instead, they either remain in the commercial health insurance system or they simultaneously pay for both commercial and public health insurance, which is highly disadvantageous. Since there are no reasonable grounds to stay outside the public health insurance, it is concluded that it is lack of awareness that keeps eligible immigrants from entering the system. It is suggested that no equal access to health care exists without sufficient awareness about health care system.