It aims to give every young child in Wales the opportunity to benefit from early years services and experiences through the medium of Welsh.
These voluntary groups are often crucial in the subsequent establishment of a Welsh-medium primary school in the area.
Mudiad Ysgolion Meithrin followed the establishment of voluntary nurseries in Cardiff and Carmarthen in 1943, and in Barry in 1951.
The expansion of state-supported Nursery Education in recent years has led to further growth.
Mudiad Meithrin has provision throughout Wales at several levels and is in partnership with local and national government.