A mother and her two teenage sons have been charged after a 16-year-old boy was stabbed in the face in Sydney's west.

The family is expected to face court on Friday, each charged with wounding with intent to cause grievous bodily harm, following the stabbing in South Penrith on Friday.

Police were called to a home in Dallas Avenue about 4.15pm on Thursday after reports that a teenage boy had been stabbed during a fight in the front yard of a home.

Paramedics arrived to find the 16-year-old with stab wounds to his chest, stomach and face.

He was taken to Westmead Hospital in a serious but stable condition.