Figures released by operators First Great Western have shown that over 14,000 journeys were made on the Atlantic Coast Line in the first 16 weeks of 2009.
This is nearly 5,300 more than for the same period in 2008 and use of the Atlantic Coast Line has more than doubled since 2005, when 5,800 journeys were made.
Increase
The rise in passenger numbers follows the increase in the number of trains on the line from four to seven a day on weekdays last December and much work by members of the Friends of the Atlantic Coast Line (FOCAL) support group.
Julian Crow, First Great Western's general manager for the west of England, said: "We've been working away quietly over the past year to make substantial improvements to the Devon and Cornwall branch line services, with better timetables, refurbished trains and reliable performance, and it's great to see so many more people taking a ride on these wonderfully scenic routes.
"With more holidays being taken at home, we're heading for a record year on our local railways in 2009."
The Atlantic Coast Line and the region's other five rural branch lines are promoted by the Devon & Cornwall Rail Partnership, a partnership of local authorities, the rail industry and the University of Plymouth.
Manager Richard Burningham said: "These excellent figures show that more and more people are finding the train a great way to get around for work or leisure, with great value local fares and the best ever train service running on the Atlantic Coast Line and the other five lines too.
"The Atlantic Coast Line, and Newquay itself are particularly benefiting because the increased train service makes it easier for tourists to arrive by rail at any time of year."
April was a particularly good month on the line with 6,700 extra journeys - more than double the number seen in April 2008.
Big increases in use have been seen on all six Cornwall and Devon rural branch lines so far this year. Overall, 355,000 used the branch lines over 2009's first 16 weeks, a rise of 60,000 or 20.4%.
Nigel Blackler, head of transportation at Cornwall Council, added: "The increase in patronage demonstrates that for many people rail can provide a sustainable alternative to car-based travel and underlines the importance of branch lines in connecting Cornwall's rural communities."