It happened behind the Avon building on Midland Avenue near the 95/287 Interchange at 5:10 p.m.
The MTA says that the cars misaligned during the evening commute.
The west bound train on the New Haven line was traveling in a slow-speed zone at the time, just east of the Rye station.
Five of the 12-car train came off of the tracks.
There were some 185 passengers on board at the time. All of the cars remained upright.
Metro-North says that several people were treated at the scene for minor bumps and bruises. They believe the most serious injury to be someone experiencing chest pain.
The cause of the derailment is under investigation.
By 6:30 p.m., Metro-North had transferred all of the passengers to another train.
New Haven Line trains are operating with delays of up to 60 minutes as a result of the incident.