Sussex Police said officers were called to the A27 at Hambrook shortly before 8am to reports of a collision involving a van and two cars.
One person suffered a minor injury, police confirmed. South East Coast Ambulance Service said no one required further hospital treatment.
Police said one lane of the eastbound carriageway was closed, while the vehicles were recovered, but has since reopened.
According to traffic reports, the crash happened on the A27 eastbound between A259 Havant Road (Emsworth Junction) and A259 Cathedral Way (Fishbourne Roundabout).
Traffic was reportedly queuing back three miles whilst the incident was ongoing.