The first station in Kilwinning was a terminus at the Byres. This is west of Kilwinning on the road west via Byres to Stevenston. The site was probably subsumed into the Ardrossan platforms at today's Kilwinning station.
A branch to the Dirrans, south and east of Kilwinning, was continued to Doura. This served the Eglinton Iron Works and the colliery on the east bank of the River Garnock.
The line was intended to continue north to Johnstone to meet the canal but was not extended, the Glasgow, Paisley Kilmarnock and Ayr Railway instead approached from the north within a few years. The Ardrossan and Johnstone Railway was reincorporated and rebuilt as the Ardrossan Railway, a standard gauge branch from Kilwinning to Ardrossan. The original terminus was probably lost at that time. The junction was just to the north of the probably site.