Three people have been taken to hospital with various injuries after a crash on the Kamilaroi Highway near Blue Vale Road in Gunnedah on Monday.
Emergency services were called to the scene at about 12.20pm, after reports a semi-trailer and a car had collided.
A 30-year-old man was taken to Tamworth hospital with back, arm and leg pain, and paramedics took spinal precautions while treating him, a spokesperson said.
The driver of the semi-trailer was uninjured, but taken to Gunnedah hospital for mandatory testing.
Five ambulance crews were on the scene of the crash, including the specialist medical team, an Ambulance NSW spokesperson said.
The SES and Fire and Rescue Gunnedah were also in attendance, as the semi-trailer spilt 50L of diesel it was carrying in a 600L tank.
Fire and Rescue crews were able to contain the leak and the truck was removed from the highway.
Fire and Rescue South Tamworth were called to back-up the Gunnedah station while Gunnedah crews were on scene.