CzechKid :

The right to remain: This is residence which a foreigner can acquire after five years of living continuously in the CR (previously this was 10 years), and there is now a legal right to acquire this residency. This means that it must be justified to a foreigner why they are not being allowed long-term residency, and the foreigner may appeal against such a decision. An important condition is that the foreigner may not have lived outside the CR for more than a total of 10 months during the previous five years. A foreigner with permanent residence enjoys all the rights and duties of a Czech citizen, with the exception of the right to vote, to serve in the army, to work in military units, and to work in positions for which the state reasonably requires Czech citizenship.

Permanent residence can also be acquired by marrying a citizen of the CR or a citizen of the EU residing in the CR, and this means a relatively high occurrence of marriages of convenience, since this is a fast, easy way to obtain long-term residence without waiting many years. On the other hand, these foreigners are regarded more strictly, and if there is any reason for suspicion, the Foreign Police may attempt to inaugurate proceedings on the withdrawal of long-term residency. In the case of the more “classic” permanent residency, such measures can be taken only if there is a security threat to the CR and in other serious cases.

Another special category is permanent residence for humanitarian reasons, which a foreigner may receive if either they or a member of their family is suffering serious health problems which are such that to return to their own country could involve a threat to their lives.