The Helston Railway Company was formed in 1879 to construct a branch from Gwinear Road to a station on the outskirts of Helston, following several failed attempts to gain support for a railway to transport tin from Helston to Penryn. With strong local backing and an agreement from GWR to operate the trains, in return for one half of the company's receipts, the Helston Railway Bill received Royal assent on 9 July, 1880. Construction had to be completed within five years.

The 13.7 km (8.5 miles) long line, which included a fine six arch granite viaduct over the River Cober at Lowertown, opened in 1887. As the mining industry progressively declined, demand from quarries, tourism and agriculture more than matched, and in 1898 the line was purchased by the GWR.

On 17 August 1903 Britain's first railway-operated bus service was launched, meeting trains at the Helston terminus to carry passengers on towards The Lizard, via Mullion. GWR's experiment reduced the pressure it was under to build a railway to The Lizard under a Light Railway Order granted in 1898 to local promoters. The GWR was not prepared to contribute towards the construction costs of the extension; although Helston station was built on an embankment, which would have allowed a bridge to be built across what is now Godolphin Road, the project costs were judges to be excessively expensive. The GWR's view had been made clear to the promoters - "the traffic of the District to be served would be insufficient (in any case for some time to come) to render a line remunerative."

The GWR had only just been pipped to the post for launching Britain's very first motor bus service. This had been launched in Eastbourne four months earlier in April 1903, thereby also establishing the world's first municipally owned motor bus service. This ran from Eastbourne Railway Station to the Old Town. The Ilfracombe Motor Coach Company had also already operated railway feeder services, on behalf of the Lynton & Barnstaple Railway - the owner of the former was the Chairman of the latter, the publisher Sir George Newnes.

GWR's foray into bus services was so popular and profitable that further routes were soon established at Penzance and Slough; by the end of 1904, 36 buses were in operation, 10 more than were in service in London. A service from Penzance to Marazion had been introduced on 31 October 1903 and ran until 6 August 1916, running beyond Penzance to Newlyn for the first few months. Another service was introduced on 16 May 1904 to St Just which was often extended to Pendeen and Lands End. In 1922 services were introduced from Penzance through St Buryan to Lands End and various villages in the area. Two years later a short-lived service ran to St Ives. In 1925 new services were added from Helston to Redruth, Gweek, St Keverne and Manaccan.

Other railway companies followed by establishing bus operations, for example Southern National and Western National. Later, railway companies moved into the aviation sector. But when the Great Western Railway (Road Transport) Act was passed in 1928, it was the Great Western Motor Services which had the largest railway bus fleet. This Act regularised the railway's operation of road services and also paved the way for them to be transferred out of the railway's control to dedicated bus companies, although the railway was still permitted to be a shareholder in these companies and there would still be an effort to integrate road and rail services. 

GWR's extensive bus routes in Devon and Cornwall were transferred to the new Western National Omnibus Company on 1 January 1929, with ownership shared equally between the GWR and the National Omnibus & Transport Company. In 1929 the railway also took thirty per cent of the shares in the Devon General Omnibus and Touring Company, while the Southern Railway took twenty per cent. At the same time, Western National routes around Bovey Tracey and Moretonhampstead were transferred to Devon General. By 1933, the GWR had given up the direct operation of buses.

The carriage of granite, coal and agricultural products remained an important source of revenue on the Helston Branch during the 1930's. During the war years, the line was used extensively for military traffic. However, competition from road transport became critical for the Helston Branch during the 1950's; the line closed to passengers in late 1962 and the line closed to goods traffic on October 4, 1964.

British Oxygen Company had lifted the track of britain's most southerly station by the end of 1965; the track bed was disposed of in sections, mainly to adjacent land owners, during the 1970s and 1980s. Much of the alignment of the line remains, with the majority of the bridges, including the Cober viaduct (now in private ownership), still in serviceable condition. The station site at Helston was demolished, but the Goods Shed is extant - now part of a sheltered housing complex - along with part of the station platform. The remaining track bed in Helston town has disappeared under development, including the Water-ma-Trout Industrial Estate. The Helston Railway Preservation Society began restoring part of the line in 2005,with a new station and sidings constructed at Trevarno.

A Transport Trust Heritage Plaque marks Britain's first railway-operated bus service at the Top House Inn (The Square, The Lizard TR12 7NQ) where the service terminated.