The guidance, released ahead of full first-quarter figures due around the end of April, compared with a 5.3 trillion won mean estimate of 41 analysts surveyed by Thomson Reuters I/B/E/S. The company enjoyed an 8.5 trillion won profit a year earlier.
The estimated January-March operating profit would mark the highest in three quarters.
Samsung's smartphone line has previously been a strong profit driver for the company, but the runaway success of Apple's iPhone 6 and 6 Plus has had a serious impact. Consumers have increasingly eschewed Samsung's plastic phones in favour of the new, larger Apple devices - hitting the South Korean company's bottom line hard.
Samsung has responded by radically redesigning its forthcoming Galaxy S6 flagship smartphone, which is due to launch this week.
January-March revenue likely fell 12.4 percent to 47 trillion won, Samsung said, compared with a mean forecast of 49.8 trillion won by the Thomson Reuters I/B/E/S survey.
(Reporting by Se Young Lee; Editing by Stephen Coates)