We received a report of a road traffic collision between a car and a pedestrian in High Street, Blaina at 12.35am on Thursday 2 January.
A 33-year-old man was taken to hospital for treatment and his condition is currently stable.
We have arrested a 25-year-old man from the Blaina area on suspicion of attempted murder and is currently in police custody.
A section of High Street remains closed to all pedestrians and traffic in both directions.
We are appealing for anyone who may have witnessed or may have information about this incident to come forward.
Please call Gwent Police on 101 or direct message our social media channels on Facebook and Twitter, quoting log reference 2000001314.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.