Under Monegasque law, citizenship is mainly based on the principle of ius sanguinis and thus citizenship is conferred upon birth to a Monegasque parent, irrespective of the place of birth. Citizenship can also be acquired through descent, marriage to a Monegasque national and naturalisation. In order to acquire citizenship of Monaco by naturalisation, one needs to provide evidence of residence of at least ten years in the principality, after reaching the age of 21. Acquisition of citizenship by naturalisation is however discretionary and granted by sovereign ordinance.
Monaco strictly forbids dual citizenship and any person obtaining a second citizenship automatically loses the original citizenship. This is also applicable under the naturalisation route, as the person seeking Monegasque citizenship must also renounce the original citizenship.
74, BD D'Italie