During China's one-child policy era (1979–2015), birth tourism in Hong Kong (HK) became a way for Chinese parents who wanted more children to avoid the regulations. From 2003 to 2012, about 200,000 babies were born in HK to mainland Chinese parents. This paper explores how the one-child policy, migration regulations, and welfare provision jointly influence family practices of mainland parents who gave birth in HK. Data are drawn from ethnographic research conducted with 45 mothers staying in HK on temporary visas to look after their HK-born children. Research findings show these parents need to negotiate with the following contradictory circumstances: a one-child policy that disregarded cultural preference for sons; migration regimes that separated parent from child and thus challenged the cultural ideal of an intact family; and welfare policies that stigmatized the parents as irresponsible in a context where families are widely regarded as care providers.