The service became profitable in May following several years of losses, and the sharpest increase in traffic was recorded on the southbound service from Stockholm to Malmö.
"This is a fantastic development," says Mr Björn Nilsson, CEO of SJ Norrlandståg, which is responsible for SJ's overnight services. "We are confidently looking at the future for our night trains."
SJ cites a number of reasons for the dramatic increase in traffic, with retiming the departure from 21.30 to 23.14 as one of the main causes. SJ's campaign to promote the service to politicians and business people in southern Sweden has yielded results.
Nilsson says an increasing number of people are appreciating the ability to arrive early the next morning and avoid the expense of an overnight hotel, especially as passengers travelling first class have an en-suite shower and toilet. Passengers can remain on board the train at the final destination until 07.00 and then have breakfast at a nearby hotel, while passengers in Stockholm have access to the SJ lounge.