This branch line was opened by the London & North Western Railway (LNWR) to provide competition with the Metropolitan line, whose influence was in the ascendancy in north-west London and beyond. The line branched off the ill-fated Watford - Rickmansworth line, opened originally by the Watford and Rickmansworth Railway (and which was absorbed into the LNWR only nineteen years after opening).

The main Rickmansworth line was closed to passengers in 1952, its demise caused by a familiar pattern of more direct and cheaper services elsewhere. The Croxley Green branch somehow survived Beeching's axe but attempts to create more traffic by providing more frequent services failed. The line was closed unofficially in 1996 when a new dual carriageway cut through the line and a new replacement bridge was deemed as not being financially viable. Formal closure was passed in 2002, albeit with the long-term intention of the line being taken over by the Metropolitan Line.

The long-term intention of re-opening the branch seems destined to remain as just that. Despite spending £71 million so far (on what?) the line is no nearer to being rebuilt. The authorisation that was granted for the rebuilding of the line wiill expire in 2018 and with funding for the line no nearer to being secured, it is suspected that the line will remain a disused one for a long time to come.

Details of the plans up to 2015 are contained in this excellent site: www.croxleyraillink.com. A more recent explanatory article is available from London Reconnections.