A 24-year-old Nelson man was airlifted to hospital with a serious leg injury and three people were transported to hospital following a multi-car crash at Whangamoa Hill, east of Nelson, on Sunday morning.

The Nelson Marlborough Rescue Helicopter and emergency services were called to the scene on State Highway 6, on the Nelson side of the hill, about 11am after an accident involving two cars and a motorcycle.

A rescue helicopter spokesperson says the on-board intensive care paramedic helped assess and stabilise the patients before a 24-year-old Nelson man was air-lifted to Nelson Hospital Emergency Department with a serious leg injury. The remaining two patients were transported to hospital by ambulance.

The helicopter was called to three incidents in Golden Bay and Abel Tasman areas on Saturday.

About 2.45pm on October 24, the rescue helicopter was called to Upper Takaka after a three-year-old boy suffered medical problems.

A rescue helicopter spokesperson says the boy was assessed by the on-board intensive care paramedic before being flown to Nelson Hospital for further treatment.

The helicopter returned to Upper Takaka just before 4.30pm to airlift a two-year-old boy with serious breathing difficulties to Nelson Hospital.

At 11pm, the helicopter was called to Awaroa in Abel Tasman National Park after a two-year-old boy required medical care for breathing difficulties.

A rescue helicopter spokesperson says the boy was assessed and treated by the on-bard intensive care paramedic before being airlifted to Nelson Hospital for further care.